22 December 2009

Drove the E up to High Point

Thanks to Chris for letting me charge up on the way to the very northern tip to New Jersey today.

Voltage at Chris' measured about 122 in the morning and 117 on the way home after dark.  No trouble charging either time.  Of course, the car would see about twice those numbers, or 244 to 234 volts. Well within ANSI specs.  Unlike at my house which  is often 253 volts and the Mini E won't fast charge.

By the way, the skiing was lousy, too many bare spots from all the wind.

21 December 2009

The cavalry is on the way

I heard today from Clean Fuel Connections that the entourage from Mini will be visiting me in early mid January.  Not just to diagnose the charging issue but with a potential work around and possibly a modified (fixed?) car to see if it has trouble with my high line voltage.  I suspect mine is the highest of the bunch who are having trouble, which apparently numbers six.  Not bad, 1% of the total.  This is the sort of problem that needs to get figured out in the prototype stage.

Now, if I can get really technical for a moment - Mike, you might remember this from your Electrical Engineering days.

You don't need a 15 kilowatt transformer to lower the line voltage to get around this problem.  A transformer with a 12 volt 60 amp output could do the job theoretically.  Wire the output in series with one side of the 240 volt line but opposing phase (symmetry is not needed) and you drop from 240 volts nominal to 228 volts.  That should be a MUCH cheaper transformer.  I'll post a schematic in a few days maybe but I doubt something like this would comply with the electrical code, so it is academic.  Maybe try it on the 4th of July so that if it explodes, it would seem to be on purpose.  Ha ha.  Maybe I can find a picture of the cavalry with some explosions?

20 December 2009

You can charge any car your want at Tom's restaurant

OK, this is about line line voltage, but not mine!

We visited Mike Graham today. His line was 244 point something volts which is well within ANSI specs, although on the high side. I could charge #458 fine, but Mike's #269 would not charge. So the over-voltage threshold in his car has drooped even lower than mine in the cold, but his line voltage is also lower than my 253ish. So we have similar problems at our respective homes.

Tom's restaurant is nearby Mike's home so we went over there to finish charging and get some DELICIOUS food and peek at his line voltage. As Tom told me, since he has industrial 3 phase power, the single phase feed is lower with a nominal of 208 volts. (For the geeks, that is 120 volts times the square root of 3, for 3 phase.) Tom's line actually read 204 point something today. And of course, no trouble charging. No one ever has had trouble charging at Tom's restaurant. Because the voltage there is lower.

Mini, are you taking notes? There will be a quiz when you make your house call. I am handing you the answer to this charging problem on a silver platter here.

Oh by the way, this long drive in a BIG blizzard. That traction control is Great. The heater is not dependable. Goes cold now and then. Need to leave the fan up on three.

18 December 2009

I hope this is the last post about line voltage

Tonight I read the power line at about 250.1 volts and the Mini E would not even blink. Had to even dig out the clothes iron to get the line voltage down to 248 before she would charge.

It is nice to know what is going on finally with this charging problem. But it is rather frustrating to deal with and not without risks. I think this is the end of the data collection for me.

I think I got word through the ramparts and into engineering at Mini, although there is no confirmation. Had to use the back door to get someone to listen, but that is the way it is most places, including where I work. It is not an ideal situation, but the engineering department can get flooded with noise and distractions if the guards did not keep the Visigoths from the door.

Last night it worked

We got home with temperatures in the low 20's, line  voltage about 252.6 and of course the Mini E won't charge, not even one blink or click.

After turning on almost everything in the house, the line voltage drops to 250.0 and bingo!  It started charging and did not stop.  I was expecting to need to get it down to 249, since recently 249.2 was not far enough down.  Sounds like 249 to 250 is the threshold when temperatures are a bit below freezing.

I heard from a reputable source that the AC Propulsion safety limit (maybe there is another more official term?  Jason, can you comment?) should be 264 volts.  That gives plenty of margin past the ANSI spec of 252 max.  To bad it doesn't hold in the cold.

16 December 2009

No dice tonight

This was a test of charging tonight. I get home at zero range (although the gauge floats back up to 11% when I turn it off) and temperature just below freezing. This is usually the worst combination for getting the fast charger to work. I measure 250.8 volts, not as high as usual, but 1.6 volts higher than last night which was warmer. So I am not surprised when Mini E #458 won't even try to charge from the fast charger. Note that 250.8 is within the ANSI standard.

I turn on all the big loads in the house. Space heaters, toaster, the few incandescent lights that have not been switched to CFLs. Voltage drops to about 250 and when I plug in the car, it blinks a few times but then stops. Well at least it tried. It noticed the difference. Usually, if it won't even blink on the first try, there continues to be no response for 30 minutes with the big wall box "charger".

So I turn on everything in the house, even open the door of the fridge until I hear it start. Voltage down to 249.2, like it was yesterday (except I didn't have to turn on anything yesterday to get down to 249.2, maybe the neighbors had something big on yesterday). The car blinks 8 times, more than last try but then it stops. Still, this makes sense, it is colder tonight by maybe 15 degrees even though I got the voltage down to yesterday's value.

OK, put it on the 120 volt cord, I am out of time tonight. At least it only needed 10 minutes on 120 volts before it would switch to the higher voltage fast charger.

I have an 8000 watt heater I have not used in a while since the sauna turned into storage space. I'll have to clean it out so I can turn it on. An 8 kilowatt load should pull the power line down by several volts. Best part is, it is just one switch, not 50 things all over the house.

15 December 2009

Voltage tolerance in North America

I did find a spec for AC power line tolerance in North America, 114 to 126 volts. So technically my power line at home which is usually at 126.5 volts is too high, but I say AC Propulsion needs to be more tolerant in cold weather right after driving.

The Wikipedia link is here. The excerpt follows:

"In the United States[3] and Canada[4], national standards specify that the nominal voltage at the source should be 120 V and allow a range of 114 to 126 V (-5% to +5%). "

[3] ANSI C84.1: American National Standard for Electric Power Systems and Equipment—Voltage Ratings (60 Hertz)

Tonight my power line read below 250 volts, 249.2 to be precise. I had no trouble charging, it started immediately and kept going. I cannot remember the last time I did NOT have trouble with the fast charger. So this supports my theory. Then again, it was not so cold tonight. Tomorrow will tell. But maybe, just maybe Wile E. Coyote (my alter ego in this context) finally caught a valid theory.

Who knows why my line voltage was below 250 tonight. Coincidence? The idea that winter voltage is higher because all the Air Conditioners are off is interesting, but it does not explain why waiting will usually get the car to accept the fast charge. Then again, neither does my theory unless it is somehow related to battery voltage. And besides, I bet the power company regulates for load conditions.

I know waiting usually will get it to start charging again. But a couple times a month I take the boss out dancing when I get home from work with 1% charge left. If it doesn't start charging right away, we have to take the gas car. And she doesn't like the gas car anymore!

So you see, Mini, I had to figure it out myself. I couldn't wait for the house call. Because tomorrow night is dancing night. And it is very important to keep the boss happy! (That would be my wife.)

13 December 2009

I finally caught the culprit

How many Mini E drivers have this problem charging from the 240 volt wall box in the cold?  Mostly in New Jersey?

Here is what I am pretty sure is happening:

The AC Propulsion electronics (the big brass box under the hood) checks the voltage when you plug it in.  If it thinks it is too high, it won't charge to protect itself, or it will start charging and then see the problem and stop.

Something about the colder weather (maybe combined with a low battery charge) is making it judge the AC line voltage (mains voltage) too strictly.  I typically have over 126.5 volts at the regular outlets around the house.  So at the Clipper Creek charging interface (or wall box), it sees twice that, which is over 253 volts.  (Please Please DO NOT try to measure this directly if you are a civilian.  There are safe meters such as the Kill A Watt which will measure a regular outlet and you can multiply that by 2 for an estimate.)

Normally I would guess the AC Propulsion box is happy if the charging voltage is below 260 volts, but in the winter that threshold has slipped down about 3% and it now thinks 253 volts is too high.  Well, our local power company PSE&G does a very good job keeping the voltage up in central New Jersey.  I don't think there really is a problem from the power companies' point of view until the voltage gets to 128 volts, but I am not having any luck finding a specification.  I just remember that from somewhere.

I think I can prove this to Mini, although they can probably verify it themselves.  Too bad, I was looking forward to the promised house call.  But I am super busy at work right now so I probably would not have time to meet them anyway until January.

If you are one of the Mini E drivers with this issue, try turning on everything in the house before you plug in your E.  The extra load should pull the voltage down a bit and might be enough to make the car judge the voltage as safe.  Don't forget to turn things off again as soon as the car has been charging for 15 seconds, especially the stove or the dryer.  I even ran the Microwave but be sure to put at least a cup of water in it, they don't like to run empty.

I switched back and forth several times, and the car would always continue charging when the line voltage was at 240 or slightly below, but back up at 253 volts it would either not start at all or only blink a few times and then stop.

After all the theories that have come and gone, I am going to be really embarrassed if this gets disproved.  But I am pretty confident this time.  The real test will be tomorrow after the long commute to and from work and the low battery charge.

12 December 2009

Throw out all the theories!

I cannot count how many theories have gone back and forth about what might be behind this charging problem.  Several have been ruled out.  I don't remember who first mentioned the cold, but I do have some evidence on that.  The first time I remember having trouble charging was Sept 25, which was also the first day that the ambient temperature was below 60 degrees when I got  home.  (See, those tedious trip logs do come in handy.)

It was also the first time I ran the battery way below 0% to see what would happen.  (That is how I remember the date, I posted a blog entry about it here.)

The only things I can say with confidence is that if battery charge is low on a cold day, I have trouble charging at 240 volts from the wall box in my garage.  Pretty much every other theory I have examined seems to be full of holes.

The last couple days were about as cold as I have recorded this season, with low twenties yesterday.  I was driving loaner Mini E # 008 until this morning, and I had more trouble getting #008 to charge than I ever had with my #458.  This morning when I got #458 back from Princeton Mini, I had just as much trouble as with #008.  The common element is temperature around freezing.

And both cars charge fine at 120 volts.

So when the engineers from Mini make a house call, we need to pick a cold day and I need to run the charge down low on the car.  Heck, they can bring #008 by again if they run the charge down, then we have two chances to figure out the problem.  Because once the car starts charging at 240 volts, the problem disappears until the next drive cycle.  And you can fix the problem if you cannot reproduce it.

On the edge of the qualifications

Some readers of this blog may get an incorrect impression from the lengths I go to when commuting in the all electric Mini E.  Those who are also Mini E drivers might understand the assumptions I am making in writing this blog, such as what the headline photo implies.  I have carelessly aimed this blog at fellow Mini E drivers.  For those readers who don't have their own Mini E lease, let me set the context.

When Mini started taking applications, it was clear that I would not be considered since my normal commute was 150 miles per day, and on the outside they were accepting people who drove at most 110 miles  per day.  Even then it appeared that they would only accept my application if they were desperate.  I worked with Google maps for quite a while and found a route to work on back roads that was about 110 miles round trip, and claimed that on my application.  It turns out that route is not passable by car, the best I  have done is around 116 miles, but normally 120 miles to save time.  I argued strongly with Mini that this would be fine since I could charge the car at work and Mini finally agreed to lease me an E, after strenuous pursuit on my part.  (I recently made the round trip without the benefit of charging all day at work, see link here.)

Being an engineer, I want to  know things, such as the effect of cold weather on the range.  In isolation.  That is, I want to know the effect of cold weather, WITHOUT the effect of the heater drawing down the battery.  And since I am already way out on the edge of the range limit, I go to perhaps ridiculous lengths to get this data without clouding it by other variables.

So let me ask, how many other Mini E drivers have even gotten a range estimate such as the one pictured  at the top of my blog?  Over 140 miles is quite rare I expect.  Maybe most drivers rarely see over 100.

Let me ask how many Mini E drivers regularly commute over 100 miles per day?  I know there are some, but I suspect it is less than one percent, and most or all are in Southern California, not the frozen North of New Jersey and Pennsylvania.  And the one I read about has a 240 volt charger at work and at home.  I have only 120 volts at work.

So when I describe wearing 3 to 5 layers of clothes, preheating the Mini E with a portable heater, and drinking 5 cups of hot tea to stay warm on my long drive, this is  NOT behavior that one should expect is required in an electric car, any more that the terrain in the above photo is likely to be encountered in your daily commute.

But some people will always test the conditions out on the edge.  By profession I am a test engineer, and recounting these adventures is a testament to my personal curiosities, not to what the average driver of  an electric car might expect.

Believe me, on the weekends we drive the Mini E just like any car, with the heater blazing, maybe without warm coats in cold weather, maybe driving hard and fast.  And many days now  I have run the heater near the end of my long weekday commute, regularly bouncing the "charge meter" off zero a few miles from home.

But on the  edge I am very careful.  And the car performs amazingly well at the extremes if you are careful.  But you don't have to be anymore careful with an electric car than with the old "fossil fool" cars if you are not trying to reach extremes of range.

11 December 2009

Mini didn't find the problem, so they are coming to visit soon

So I have the snow tires and decals, but they did not find the problem that causes #458 to balk at charging from 240 volts.  So they say they will make a house call.

I'm not sure they understand that the car has to come off a long drive and be at low charge to have a high likelihood of not wanting to charge.  I'll make it clear when they come to visit.  Actually that might make it tricky to set up a visit with those conditions.

Michael with #249 says he has to wait between 10 and 60 minutes to get his Mini E to charge at 240 volts.  But this loaner #008 I have is worse.  For the two days I have had it, it won't even try at 240 volts when I get home, no blinking that stops after several seconds, nothing.  But of course it is happy at 120 volts.  And I have waited over an hour now.

I think the engineers from Mini might have a better chance reproducing the problem if they bring #008 over to my house after driving it to a low charge.

10 December 2009

Same problem charging, new car (temporarily)

Well, loaner #008 does not have the problem that my #458 has with the rear defroster killing the radio with static, but the charging issue is even worse on #008 than on my #458.

Otherwise it drives exactly the same. Gets more notice with those decals.

09 December 2009

I get #008 as a loaner? Not #007 ? But my name IS James!

So my #458 went in for 13,000 mile routine maintenance today, and Jimmy G at Princeton Mini managed to get me another electric Mini as a loaner. Wow. Very nice. But maybe there was a practical reason in addition to Jimmy being such a great guy...

You see, I have been having charging trouble with #458 as a few others in New Jersey have. It has gotten quite consistent lately. Most days I get home and the Clipper Creek wall box trips the Ground Fault Protection when I plug in to charge, and the red indicator lights up on the wall box. At the very least, the wall box stays on but the Mini E's yellow charging light stops blinking after only 6 seconds, 8 seconds at the most.

Tonight I got home with loaner #008, pull into the garage and guess what? Six yellow blinks and the car stops charging. It did it twice. Third time and it goes on to complete charging. That is a fairly normal scenario when my #458 has trouble, unplug and try again a few times and it is OK. Sounds like the problem is in more than one car, and maybe something about my place makes it act up? But what could it be? The line voltage does not drop much when the car starts charging, I have measured it. And the 120 volt slow charger always works.

There was one funny thing today though: When I got home from work and plugged in before going to the dealer to drop off my #458, I parked OUTSIDE my garage and did NOT have trouble charging from 240 volts for the first time in WEEKS. But the loaner did have trouble when in the garage.

This is getting interesting. I rained very hard last night and today, but the sun came out on my way home. However, it usually takes days of warmer dry weather for the charging problem to go away. (My theory is moisture in the wiring or in the battery modules is causing a Ground Fault Interrupter to trip.)

So could there be a difference parking outside on the blacktop driveway that was in the sun versus inside on the damp concrete? Maybe damp concrete is a better conductor than sunny bitumen and with damp tires, any leaking electricity could get to ground and trip the safety protection and stop the charging? I don't usually get home when the sun is still up but I left early today so I could get the loaner on time.

OK, I'm not going to do anything for a couple days so I can see if things with loaner #008 are exactly the same as my #458 or not. (Hmm, maybe this is WHY they loaned me another electric Mini? To see if it has the same problem with my charging box?) Over the Christmas break I should have time to make some measurements in the Clipper Creek wall box with an oscilloscope, current probe and high voltage differential probes. But it is too busy right now, and I hear that Mini has started sending engineers to the garages of some Mini E drivers that are having charging problems. So maybe they will get to it before I do. I hope so. I am an electrical engineer, and I have a healthy fear of high voltages. I would rather they figure it out, but I am getting excited about fixing this and I might not be able to wait...

I can't stop wondering what would happen if I dry out the inside of the Clipper Creek box with a hair dryer. I had to do that months ago with the little yellow portable charging box, and it worked perfectly. (For the post about that episode click here.) But even if something like that works, it does not give specific enough information on the root cause of the problem.

Or maybe I will park on pieces of wood to see if that insulates the car and stops the Ground Fault trip. At least that would not destroy evidence like the dryer might.

Ah, I know! Next time it trips and the red indicator lights up on the Clipper Creek wall box, I will measure from a metal tire rim of the Mini to ground and see if there is any voltage that could trip the GFI. Charging always works after letting it sit for ten or twenty minutes, maybe that is long enough for the tires to dry off? If this finds leakage, I bet the leakage it is out of phase with the hot line from the 120 volt charging cord. That would explain why it only has trouble with 240 volt charging, the only wire that is leaking is the one that is grounded on the 120 volt box.

This sure is getting interesting. The solution is so close I can almost smell it. Being an engineer is fun. The future is almost here!

Anyway, they probably didn't make a # 007 Mini E... Or a # 013...

05 December 2009

Hard data on the heater

Robert with #304 posted a great article on the heater in the Mini E.  It says the "PTC" heater (I think that means Positive Temperature Coefficient) can put out 3000 watts.

Mini said at first that the battery has 30,000 watt hours of usable capacity.  (Later reports indicate slightly less if I recall.)

So running the heater at maximum for one hour should consume 10% of the range.  I have never run it at full for more than a few minutes, I usually back off to half at that point.  But theoretically, this means the two hour driving range (usually enough to drain the battery fully) might shrink to an hour and a half roughly, if it were cold enough to run the heater at maximum the whole time.  At lower settings, the range reduction should be less than 20%.  Maybe much less.

I measured heater power usage at low fan settings and posted them way back in September here.  But this morning I measured again at the highest fan and heat settings with the windows open.

After 80 minutes at max heat the charge meter dropped 18%, which is a bit more than theory predicted above, but reasonable.  It was in the upper 40s Fahrenheit and I left the hatch open.  Temperature one inch from the heater vent was above 110 F with the fan at max, and the temperature was higher when the fan was slowed down.  At fan setting #2, the temperature went off my scale, above 130 degrees F.

I have stayed away from using the heat on long drives.  This is partly because of the reports other bloggers have posted about reduced range, but mostly because I'm from Minnesota where only the weak use the heater until the weather is below freezing.  Ha.  But I'm starting to think I can afford to use it more on my long commute.  These numbers are encouraging.

While the charge gauge is pretty reliable, I find it to be pessimistic early in a drive and I almost always have more range than it indicates.  I wonder if the calibration gets worse when the heater is on?  This might explain some of the concerns that seem worse than the numbers I took.

One technical point about a "PTC" heater.  It is designed not to overheat.  So if you run the fan on low and turn the heat all the way up, the resistance of the heating element increases so that won't over heat and burn out.  My measurements showed that the heater can maintain a 60 to 70 degree increase in temperature at the highest fan setting.  But often I run it on lowest fan, and I notice it heat up and then cool down to just warm.  This is what it is designed to do.  Like Mini says, use at least the second fan setting with higher heat settings or the element will not reach maximum heat output.

By the way, 3000 watts is about 4 horse power.  The 120 volt AC heater that I use to preheat my Mini E with "shore power" is 900 watts, and I usually run it for a couple hours by timer before I leave for work.

04 December 2009

120 miles and freezing at the start

I have  almost 13,000 miles on #458 and it finally happened - I got to work (60 miles from home) and unexpectedly had to head back home without charging the Mini E.

No Problem!  I had even used the heater for half of my trip to work, something I rarely do but it was 29 degrees F on my way in and I did not have the hot drinks I usually have in the car to stay warm.  So I ran the heater some after the cabin cooled off.  (I had preheated the cabin to 88 that morning as usual, but after 20 miles it drops into the 60's.)

I have driven my commute several times very gently to see what I could do for range, so I was confident.  I had plugged in at work but left after only one hour, so I added only about 4% to the charge before I left again for home.

I took back roads and really took my time.  I have a column in my log to record how aggressively I drive, this is the only time I ever put down a "one" on the scale of one to five.  It was mid morning so traffic was light but I still annoyed a few people by going slowly.  On highway 12 in New Jersey, I drove maybe 30 mph and pulled onto the wide shoulder to let others pass at the 50 mph limit.  On the big hill I got in the truck lane and crawled up at 20 mph.

And I arrived with 1% charge left.  I even used the heater for the last 3 miles.  I know there are ten miles left after the gauge hits zero, but I didn't need it.  All in all I drove 124.6 miles, using the heater at the middle setting for about 30 miles.  Starting temperature outdoors was 29 F, ended at 49 degrees with 58 degrees in the cab.  In the middle I charged for one hour at 120 volts 12 amps adding only 4 miles to the range.

Despite the minor issues with this prototype car, we love it.  It has never let me down, even when pushed to the extreme in cold weather.  And I bet Mini will fix the minor charging problem next week when it goes in for the 13,000 mile checkup.  Actually, it is getting to be a bit worse than minor.

29 November 2009

109 miles on the freeway with 24 miles left.

We drove from central New Jersey to central Long Island New York yesterday. The trip was 108.7 miles, arrived with the dash board display estimating 24 miles remaining at 19% charge.

We thank the drivers of #351 for generously allowing us to use not only their 50 amp charger, but also a regular 120 volt outlet for a small cabin heater. I took data while the car charged, something I have long wanted to do. The graph is above, a larger image is here.The gap near the beginning was while I plugged in the cabin heater.

Both my wife and I were surprised how easy it is to drive 55 mph or less on the New Jersey Turnpike and all the roads through New York city and Long Island. I averaged under 40 mph from door to door, which explains the very good range of about 133 miles. I had one person honk at me near a toll booth and only two or three people flash their lights. But an astonishing number of other cars fell in behind me in the right lane at a comfortable distance back and just STAYED there! Being the thanksgiving weekend there was plenty of traffic, the Southern State Parkway backed up a couple times each direction. Not sure what this might be like during rush hour...

Of course we did not use the built in heater while driving until very near our destination. See my previous posts about staying warm on long drives. Of course on shorter trips we use the heater as in conventional cars since there is plenty of juice available.

26 November 2009

We have 3 choices, but we always choose the electric

I want to echo something that other bloggers who have multiple cars have mentioned.

My wife and I each have a conventional four cylinder car. Both cars work fine, both get over 30 miles per gallon. But they don't get used much since the Mini E arrived.

Like other electric car bloggers, the first choice for us is always the Mini E. Shopping is fine, there is plenty of room. Besides the far back which holds at least three grocery bags, there is a surprising amount of room UNDER the seats. (Be careful to comply with Mini's instructions NOT to block the battery vents by piling up things BEHIND the seat). If you take a regular paper grocery bag and fill it only half full with the top folded down, it will probably fit nicely under the seat from the back. Depends on how far back you put the seat maybe. Of course, if only one of us is out shopping there is lots of room in the passenger area. I have to buckle the passenger seat belt if there is a heavy bag on it to stop the seat belt reminder. But my wife and I usually shop together and there is still plenty of room.

Now, we are not the types who do all of our shopping at one store. We tend to buy produce at our locally owned, small "Organic Only" store, there are some things we prefer to get from Trader Joe's, some things from Whole Foods market, and a few things from the main stream Shop Rite or Stop & Shop and so on. And since most of these stores are in different directions, it is easy to go home between trips and unload.

And on almost every other trip we make, we will take the Mini E if it is around. It is always charged, our kids are grown and out of the house so two seats are enough. So shopping, going out dancing or to the movies or a restaurant, to church, to social events, it is always the Mini E. And the range is more than enough. My 120 mile round trip commute to work is the only thing that gets close to the range limit. The only exceptions so far have been going to the airport. Well, even for that we usually take the train anyway since it is cheaper than long term parking and often as fast.

For many years we have had three cars in the house. One for the kids and one each for us parents. We are keeping three for now since the Mini E is experimental and a backup is required. I don't know how many families are really single car households, I bet not many in the middle class. I expect most have at least two cars these days except in dense city centers. I bet for most multi car households, a 2 seat electric would be the car of choice for daily use as it has been for us.

We have needed the range of the gas car just once in several months for a long trip.

Rain strategies and charger sharing

I have had three visits now from other Mini E drivers stopping by to charge up, two of the three were traveling for business. I expect to start calling around to charge at other locations soon. Thanks again for the charger sharing site, whoever did that.

Since the heavy rain last week and drizzle since, I have been having a little trouble getting the Mini E to start charging at 240 volts again. For quite a while while it was dry I had no trouble. But whenever it refuses by blinking a few times and then stopping, I can always get it to charge from the 120 volt cord right away. After a few minutes of that (when I assume the damp connectors are drying out) it will continue charging when I switch back to 240 volts. So for me this continues to be little more than an annoyance, althogh I know other driver are quite frustrated by the same or worse troubles.

Mini, have you figured out which cable is causing the problem yet? Hmmm? Is engineering working on this? I might have to get out my hair dryer and figure it out for you soon.

A word about the windows fogging up in the rain when using the recirculate button to keep the car warmer: One big advantage of preheating the car with "shore power" and a small 900 watt car heater is that it really dries out the car. It also takes a lot less battery power to maintain warmth in the car than it does to heat it up from cold, so there is little range impact.

But when the windows eventually fog up as the car cools down, I have good luck simply using the fan on lowest setting with no heat and the air directed to the windshield. It has been raining for days in NJ and PA, and still I can complete my one hour and 40 minute drive to work without using the heater at all,and keeping the front and side windows clear by only using the fan about 20% of the time or less. The rear defogger is another matter, I am finally starting to use that. I need to measure the rear defogger power consumption one of these days...

19 November 2009

The pattern is clear: Moisture

Forget cycling the ignition when there is a charging problem.  The cause  is moisture.

Mini, are you not doing the main work in southern California?  What "The Firesign Theater" called "the stinking desert"?  You guys need to take a Mini E up to Seattle and drive it around in the rain until you see this charging problem.  Here is what happened to me tonight, and I have seen it before:

Come home in the rain, wipers on fast for much of the drive.

Plug in the car.

The RED light comes on steady on the Clipper Creek wall mounted safety box.  (The GFCI tripped, but I ask that civilians please do not open the box to look at the LEDs.)

Unplug and plug back in, same RED light.  Sound like moisture to you?

Try it again, the Clipper Creek box stays on (GREEN light) and the car starts to charge but stops after 5 seconds.  OK, something dried out enough to keep the Clipper Creek box happy but the AC Propulsion electronics in the car sees the leakage now.

Unplug, try again, same thing.

Turn down the current to 12 amps, same thing.  Of course if it is moisture, the leakage is related to voltage, not to current.

So I get out the low voltage charging interface, the portable 120 volt box.  It charges fine.

After 30 seconds I switch back to 240 volts.  The car stops as before with the Clipper Creek wall box still on.

Switch back to 120 volts, where presumably the leakage current is lower and it does not set off the safety trip in the car.  Let it charge for a couple minutes while presumably drying out whatever got wet.

Switch back to  the 240 volt wall box, and all it well in the world.  It keeps charging.

Turn up the current to 50 amps.  It keeps charging.  Of course, since leakage is not related to - what?  Yes, not related to current but to applied voltage.

OK, Mini, you have moisture infiltrating on the AC side of the Power Electronics Unit (PEU).  My guess is either at the connector to grid power on the back drivers side, or under the hood at the PEU.  It cannot be after the PEU because the voltage is always the same on that side, only the current changes.  And we know that leakage is proportional to what?  Right, the voltage.

Is it time for  the big caulking gun?  Maybe.  Mini just needs to get it right on the production cars, I can deal with this.  This car drives more confidently than any other car.  Period.  I can deal with slight lack of confidence in the charger.

08 November 2009

Charge problem? Cycle the "ignition"

Last night after a friend test drove #458, we had trouble getting it to continue charging again.  I measured 252 volts at the contactor (not recommended for civilians) but it would not charge more than about 5 seconds.  So I tried a tip from a very old posting on the Facebook discussion topics, I turned the car On and then Off.  Eureka, it started charging just fine.  (At 50 amps.)

OK, maybe it was coincidence.  And Mini did respond to my email about this, saying they are looking into it.

So the problem is getting less severe for me, nine out of ten times it charges fine.  And I have not had the red  light on the wall box for a long time.  I suspect we'll get to the bottom of it soon.  I hope Mini gets it fixed before Michael with #269 gets too frustrated.  Hang in there Michael!

05 November 2009

Three tries to start charging tonight

Maybe it was the rain, I don't know. Almost 5 minutes passed tonight from turning off the Mini until plugging in the cord, and then 5 blinks and charging stopped. I waited 15 seconds and tried again, still no go. I came back in two minutes, plugged in again and it started up and kept going this time.

I have not seen the red blinking light for awhile on the Clipper Creek box that others have reported lately. Maybe the AC Propulsion box can sense leakage itself, and stops charging. (This is my moisture theory, it was raining tonight.) I guess I should leave the key in so the display will light up in case there is an icon or message.

I did look at the charging port with a flash light but there did not seem to be moisture. Maybe I should take a hair dryer to it anyway.

Since I had this problem before and after the flying doctor changed my Magic Box last time, I suspect the issue is in the battery (moisture?) or just a software problem. I am not buying Mini's guess in their last email that the voltage from the power company is low. When that happens, the Clipper Creek box stops the charge and it restarts by itself. The problem I am seeing is the car stopping the charging process and it won't restart until the connector is removed and reinserted.

Secret "weapon" revealed

OK, Mini did a fine job with the E but every prototype program has some rough edges. One thing they did not do well was HEAT. Maybe there is a kilowatt of waste heat from the motor and some could have been recovered for cabin heat. Maybe battery heat could have warmed the cabin instead of being vented outside. Maybe a reversible heat pump instead of the the AC pump could have warmed the cabin without so much impact on the range.

Too Bad. I am happy I got a Mini E anyway. I'm sure the production version will be better.

And the photo above is one way I say "I am a pioneer!". I'll post a photo of my Sorels later. Just started wearing them this morning. Sweet on the feet, and you know what? There IS enough room on the accelerator pedal for the King of snowmobile boots, without hitting the brake at the same time.

The only time I used the heater in today's cold weather was when the windshield got foggy in the rain. And all it takes is maybe 3 notches up from the coldest, which is in the middle of the blue range of the knob. Yes, there is some heat when it is still in the blue, at least as far as the windshield is concerned. Doesn't affect the driving range much until you get to the red. And yes, that is 3 notches while keeping the recirculate on as much as I can.

By the way, I wonder is the auto off for the recirculate is needed in summer to keep the batteries cool? Mini, can you kill the auto off for the recirculate when the ambient and battery temperatures are cold? Thank you.

I have not decided where to "wear" my heater, shown in its fully charged shape. Lately I wear it under my sweater. Lap is possible, not as effective maybe. Maybe I should try it on my head? No, too heavy. I believe the most common use is for feet while sleeping. Can't do that while driving, hence the Sorels.

I am seeing some reduction in range, but I think it is mostly because the change in time (driving home in the dark since daylight saving time ended) has cost me my patience. I am driving faster. But maybe it is the cold.

With some luck I will put away the hot water bottle soon. The facility manager at my work place has a quote from Clipper Creek on a 208 volt 50 amp "EVSE" (charging interface box) just like the one Mini installed in my garage. I should know in a week or so if they will put it in or not. If they do I can go back to living like there are no seasons, wearing short sleeves in January. Ah, the good life, huh?

Something in this Minnesota boy LIKES wearing wool underwear and driving with no heat. Especially when it takes money away from oil producing countries that hate us. And I like to show mother nature that "I am a pioneer!"

02 November 2009

I have not explained the issue clearly enough to Mini

Mini sent their weekly email, which basically said that if your car does not keep charging just wait and it will restart by itself.

I doubted this in a reply to their email but I don't expect them to answer.

And I had the issue again tonight. I waited as they said. 30 minutes and it did NOT restart. I pulled out the plug and stuck it back in and all is well.

It is increasingly clear that my issue is time between turning off the car and starting to charge. It is not (in my case anyway) low voltage from the power company. When I plugged in tonight the car started blinking as it does when charging and then stopped after a few seconds. Both power phases were slightly above 125 volts and within 0.2 volts of each other, so that is not the issue as Mini suggested in their last mass email.

For over a week I made a point of plugging in the car the moment I turned it off and had no trouble with charging. Today I went back to taking my notes before plugging in which means several minutes wait after turning off and before charging, and the problem returned.

I will start timing how long of a delay from power off until plugging in a then log whether there is an issue with charging. This should give Mini enough info to reproduce the issue. In any case waiting does get around the problem but not without intervention. I do need to remove and replace the connector.

30 October 2009

Dirty power problem?

OK, there is a new theory about the occasional problem getting the Mini E to start charging at 240 volts.  The symptom I have seen is that the car starts charging but then stops after a few seconds.  Once it starts and charges for more than 10 seconds then it was always good to get to 100% charge without intervention.  But a week ago I often had to restart charging several times to get it to keep going.  The 120 volt slow charger always worked.

Recently I have heard two reports of exactly this behavior when trying to charge from a generator.  (I need to go back and ask if this was at 120 or 240 volts.)  So maybe the AC Propulsion electronics are fussy about noise on the power line, or an imperfect sine wave from the power line, or maybe the two 120 volts legs that add up to 240 volts are not exactly the same magnitude?

Mini, is anyone looking into this?

I have not had trouble for a week now.  Then again, the static I was getting on the radio at home is gone too.  Maybe someone in the neighborhood was using some nasty power tools or a welder or something?

But this needs to be fixed before the production versions of electric cars come out next year.

25 October 2009

Brown out protection

We had a visit yesterday during the rain from Don (#364) who stopped by for a recharge. While we were eating diner, I noticed the lights dim for a second. This is not unusual during a lightning storm, but I went to peek at #364 and sure enough, the Clipper Creek box was doing its job and stopped charging for a minute. A few mintes later it restarted automatically. I had not witnessed this before.

This is a built in feature of the Clipper Creek box that goes beyond what the Society of Automotive Engineers require in specification J1772, which governs Electric Vehicle Service Equipment. The interface box (EVSE) detects brown out conditions (probably due to a lightning strike or someone hitting a power pole in the rain) and suspends charging for a random time, making it easier for the utilities to get power back up to specified voltages.

This is not a big deal yet, but when there are millions of electric cars on the road, this will be one of several Big Deals for power grid stability.

And you guys that are complaining about the empty space in the box (many on the Tesla forums) - the Clipper Creek box was designed back in the 1990s in the era of the EV1 from GM. Back then, the electronics to do all the safety functions took up all the room in that box. They redesigned the electronics onto a smaller board when this second wave of EV's started, but with the low volumes at present, it does not make sense to tool up a new casting for the enclosure when the old one works.

And I wonder if maybe the extra room in there might come in handy for the Vehicle to Grid functions that are coming, and other smart metering that can save us money as drivers? We'll see.

24 October 2009

Taking the freeway round trip for the first time

Winter is coming and although I love driving the back roads to work, the hills can be dangerous when it is snowing hard.

So for a couple days I took the freeway round trip to work to see if I can make it.  On Thursday I made it home with 10% left, but I hit all the lights and was at work (charging on the 120 volt cord) for maybe 9.5 hours.  Friday I left a bit early so I only charged 7.3 hours and I didn't hit all the lights.

Coming home on I78 into NJ from PA, the highest point is a couple miles before exit 12, around my midway point.  Knowing I had nearly 40 miles to go, I laughed when the miles remaining said 9.  It is down hill now.

Over the next ten miles the remaining range indicator went UP 10 miles as I knew it would.  I had never seen the "critically low" warning go off without charging from the wall box.  But out it went, with 19 miles remaining.  (By "critically low" I mean the warning that comes on below 10 miles remaining.)

Now I'm off the freeway.  The miles remaining gauge is not going up any more, but it is not going down much either.  For nearly another ten miles it almost holds steady.

At about ten miles from home, there is another minor peak in the Sourland Mountains, and my gauge hits zero.  I laugh again.  I know that there is about 10 miles left after zero although acceleration is limited.  But of course, the needle starts creeping back up as I regenerate my way down the other side of the Sourlands.  I got home at 3%.

Still, that is pretty tight but I know of at least 2 places of business that have let me plug in on the way home if I get in trouble.  And that 10 miles after zero is reassuring.

But I have not used the heater much in days.  We will see how long I can hold out as the weather gets colder.  

I'll talk about my secret weapon, a low tech portable auxiliary heater, in future post.  It costs only a few dollars, "recharges" in minutes, lasts for hours, but both driver and passenger need a separate one.  And you might call it Dorky.  

"Embrace your inner Dork, and let the Magic Begin!"

By the way, the shortest freeway route for me to work adds over ten miles versus the shortest back road route, but this route is still only about half on the freeway.  It ends up around 136 miles round trip and only saves 5 or 10 minutes.  I drive 55 (remember that?) and have not had much trouble from other driver since I stay in the right lane.

21 October 2009

Update on minor charging problem

I heard from #364 that he regularly has a problem starting the car after it has been off for only several minutes. The talk is that the battery pack goes into cell balancing mode or something for a few minutes if it thinks you are gone. Wait just a few minutes more and everything is fine. Can be a problem at times.

I noticed this once when I ran a short errand. The current theory is that the same thing can happen to the charging process. I usually take a few minutes when I get home and write down every number I can read out of the dash display, and some other things (see the link for "#458 Trip Log" at the right). So as the battery pack ages (I am at about 8500 miles now) the cell balancing happens more often. Two days now I have tried plugging in the charge cable as soon as I get out of the car, and both times it has charged all night. No problem.

This could be random, we will see in a few days.

Mini, any comments?

Any other drivers had these observations?

By the way, after some measurements and a talk with the good folks at Clipper Creek, I am certain there is nothing wrong with the wall box.

18 October 2009

Interior preheat

Several Mini E drivers have expressed range concerns due to colder weather in the North East and using the heater in the car. I have used an interior heater for years that I bought from Napa to preheat my cars so I don't idle them to warm them up, don't have to scrape the ice off, and don't freeze on the way to work while the antique combustion engine warmed up.

Now I use it to increase my range in the Mini E. Here is a link to something similar to what I have:

Kat's Automotive Interior Heater 120 Volts #37100 $64.45


My particular model might not be available anymore. It draws 6.75 amps, or about 825 watts, the rating is 900 watts as is the link above. I plug it in when I get up in the morning and by the time I am ready to leave the car can be pretty warm, usually over 80 degrees F. When the weather gets colder I will probably go back to using a timer to turn it on before I get up. Preheating the cabin lets me run without any heat for the first ten miles or so, and then use a lower setting than I would have.

I have added cabin temperature to my logs, as well as heater settings. The link is over to the right under "#458 trip log only". Sorry about the confusing layout of the spread sheet, I'll rearrange it someday. Recent entries are at the bottom, unlike these blogs.

Mini says they don't want accessories installed, so I have my heater sitting in a steel pan that is meant for baking bread. It holds the heater at a safe angle and allows it to be positioned such that it won't melt anything like seats or the dash board. There is a thermal cutoff switch and maybe another safety feature in mine, I hope the link I found is as well equipped but I don't know, it is just a suggestion. The instructions for mine explicitly say it should be screwed down in such and such a fashion, and I have put the required mounting in my GM car. Maybe can move it to the Mini, I'll have to check with the service guys for permission.

And don't underestimate the power of taking hot drinks on your drive to increase your battery range. Liquids are also good for your immune system during flu season. And you can often run the heater at a much lower setting.

The rain here lately has put a stop to using the recirculate button to reduce the heat setting. Others have observed this causes the windows to fog up. I doubt that using the AC and the heater would use less power than turning off the recirculate. That would be interesting to try to measure...

But I do have to make some more measurements on heater power consumption. If someone else doesn't post it first, I am going to park the Mini E in the cold with the heater on at maximum, windows partly open, and time how long it takes to draw the battery from 100% down to 30% or less. Probably at fan setting 2 to start, although I rarely have to use more than the lowest fan setting after preheating.

Was anyone besides me expecting Mini to have used a heat pump instead of a resistive heating element? Too bad, but maybe it is not practical yet.

15 October 2009

Maybe it is the wall box?

Mini E #458 came home from service today.  They said at first that maybe the charging problem was the wall box, but then they found a trouble code so they replaced the big brass colored box under the hood again, like they did a couple months ago.

Except this time we get it home and still have trouble getting it to start charging.  The charging light on the dash board blinks a couple times and then it stops.

So I suspect the contactors in the safety box on the wall have gotten crusty or something.  Turning the car down to 12 amps makes it keep charging.  Then after it has been blinking steadily for more than 12 times, it can be set back to 50 amps and it will keep going until it reaches 100%.

The portable 120 volt 12 amp charger was always a bit finicky, sometimes it would take a couple tries to get it to start charging.  For several weeks that is all we had.  When the big wall box came, at first would always start the car charging immediately and keep going.  Now it is the big wall box that is finicky.

Good to get all this ironed out before there are millions of electric cars on the road.  That is what us "pioneers" (as Mini calls us) are here for.

I heard that since contacts cannot be plated with cadmium or other nasty materials anymore, it is harder to make high current relays reliable.  Maybe I have an example.  But good relays can be made, the just cost more now, or have to sealed better, or whatever.

10 October 2009

I have continued to have trouble getting Mini E #458 to start charging from the 240 volt wall box when the battery is below 30%, which happens every work day. The small 120 volt portable charger always works, and after running it for a while I can switch to the 240 volt unit. So something is wrong and tomorrow the car goes in for a checkup.

Then something new a couple days back. My wife took the "spirit powered" Mini E to work so I could take her conventional "fire and brimstone" powered car in for service, since her dealer is near my work place. Her drive is one tenth of mine, which is as it should be. So she got home with over 80% charge remaining on the Mini E, and she still had trouble getting it to start charging. I turned the setting down to 12 amps with the 240 volt charging box and this time it kept charging, but that might be coincidence.

Often what happens is that it will start charging but then stops after the blinking charge lamp on the dash has blinked 6 times. Sometimes it will go for ten blinks and stop. But once it blinks for more than 12 times, it will keep going until the battery is at 100%.

Maybe my little experiment awhile back running the battery way down weakened some of the battery modules? We will know soon. The "flying doctors" at the dealer are good, I'm sure they will fix it pronto. And I'm sure the production electric vehicles to come will not have this issue. Which is why we are doing this, after all. For the future! (Can you tell we are having fun?)

Update:  I recently found several more blogs from other Mini E drivers (I hope I have them all linked on the right side now) and I read that several others have run the battery "below zero".  Nobody mentioned ill effects from it.  So I assume that my charging issue (which mysteriously disappeared for a few days) is unrelated.  Service appointment was postponed until tomorrow...

I drive the Mini E quite a lot, maybe too much. I have driven it about 8000 miles over 4 months. So it has started to feel like a normal car to me. And when I get in a conventional piston car again, I wonder how I ever was able to stand it. Sort of like when someone says "how did we live without mobile phones?" OK, it is silly but that is the feeling. Feelings can be silly.

Now my wife only drives the Mini E on the weekends, and she still marvels at how much more welcoming it is, and easy to drive. Yesterday she was searching for words, and said something to the effect that she feels she could do anything in this car, like drive across the corn field we were passing, since everything else is so effortless.

I was starting to wonder if I should check to see if there was something funny in her green tea until I realized that I had become accustomed to the luxury of electric drive, while she was still marveling at the difference from combustion drive.

BMW, listen up! You should investigate using electric drive EVEN WITHOUT much of a battery. Just put a generator on the engine and an electric motor on the wheels, with the smallest battery in between that you can get away with. It will sell on the basis of improved drivability alone. There is a market for this beyond the environmental nuts like us. And it will help obtain economies of scale in the electric drive train.

This is most notable off the interstate highways, and on hilly roads. Despite cruise control, a conventional car requires you to reach for the brake on downhill sections. Even with an automatic transmission, the shifting is always noticeable on hilly slower roads. Not so with electric drive. The marketing guys should use the word "effortless".

07 October 2009

Charge while eating?

I was at a restaurant recently when I was low on charge.  I noticed an outdoor outlet right next to an empty parking spot.  I went inside and asked if I could plug in, and as usual the answer was yes.

Except that this outlet was the exception, it was not working.

Reminds me of the old saw, "the spirit is willing but the flesh is weak".  Something like that.  Here is becomes "the management is willing but the maintenance is weak".  Ha ha.

I got home with 15 miles of range left.

29 September 2009

Charge time at 240 volts 12 amps

A few days ago I posted results from running the battery way down past zero.  And then I charged it over night at 12 amps with the big 240 volt charger.

It took about 12 hours to go from zero to 100%.  This is much less than half of the  charge time at 120 volt 12 amps, which I measured at well over 30 hours back in the heat of summer.  See an older post.

But it is cooler now, and the battery fan runs much slower.  I suspect that is the major difference.

One of these days I will analyze my log file (now posted in with the blog links on the right) and see if I am getting noticeably more juice into the battery at work in this cooler weather.  But I can't do it right now, I am spending too much time driving my Mini E.

By the way, I am noticing some trouble getting the Mini E to start charging from the 240 volt big box when the car is set for 12 amps.  Sometimes it starts and stops, and I have to pull out the plug and put it back in, sometimes twice.  At first I thought that was because I had run the battery down so far in the experiment a few posts back.  But now I notice it even when the battery is above 25%.  Maybe it has always been like this, and I only noticed it with the small 120 volt charger that can only be used at 12 amps.  It is only recently that I have started just leaving the car set for 12 amps almost all the time because it usually charges fast enough overnight to reach 100% by morning.  The idea is to draw most of the power late at night when the grid load is low.

Staying warm

Mini wants the air recirculation control off most of the time.  I agree generally, especially in combustion powered cars where carbon monoxide poisoning is always a danger.

But in the Mini E the story is a little different.  First, the colder September weather now  in the North East US means using the cabin heater.  And I can stay warmer while using less power when the air is recirculating.  Besides, the battery ventilation is always pulling air out of the cabin, even if only through air leaks when the air is set to recirculate.

Now I would like to use heat with the cabin air fan off, since the lowest setting is still too high for these 40 degree mornings.  The battery fan draws enough air though the cabin ventilation vents. But the heater won't come on without the cabin air fan being on.  So the next best way to reduce cold air ingress is to use the recirculation button.

Of course, Mini set it on a timer to turn off after 5 minutes or so. When I notice it getting cold again, I push it again.

There are conventional Minis where I work, so I'll have to ask if this functions the same way on the gasoline powered models which have waste heat to spare.

I would like to see a reversible air flow where battery heat could go into the cabin, but maybe that would not work.  Maybe that was too much to get into a prototype.  In any case, the heater load appears to be much smaller than I expected.  I always assumed the heater in winter would be the Achilles' heel of electric cars.  So far from my measurements (see earlier posting) the heater load looks small. 

25 September 2009

Running on empty

Today I heard that I will not get one of the left over charging stations to install at work since I work in Pennsylvania, and the Mini E program is only setup to supervise charge station installations in NJ, NY, and CA. Fine, I understand.

So it is time to see what happens when you drive a Mini E well past zero.

In a previous post I noted that it can take awhile to actually get the gauge to stay at zero. When it first reaches zero, it tends to bounce back up as high as +3% when regenerative braking is used or just when standing at a stop light.

Tonight I purposely kept driving past the point at which the gauge stays at zero. With the heater running. Just driving around the block by my house.

I got almost another ten miles as the maximum power slowly declined. There is not a road speed limit per se as the charge drops below zero, but a torque limit that gets greater. So you can still go fairly fast on level road or downhill, but I got to the point where a moderate hill limited me to 15 mph.

The real issue is that it doesn't want to start charging when it has been driven well below zero. I finally pulled out the 120 volt portable charger, and it would accept charge from that. After a few minutes charging at 120 volts, the car would accept 240 volts at 12 amps. Then I bumped it up to 32 amps. No problem. A few minutes more and I bumped up to 50 amps. OK. But it was almost ten minutes before the gauge went above 0%.

Also, the charge gauge needle never drops below zero while driving. That range between Zero and Off is not a "negative zone". It just makes it clear when the car is on or off. The digital gauge never shows negative either.

So I am not worried about shorter range in the approaching winter. I can make do with the 120 volt charger at work. My 120 mile commute has usually left me with 20 miles of range when I get home after also charging at work with the little box. And I can get over 30 miles left when I arrive home if I am careful. So as the heater gets used and colder weather reduces the range a bit, I'll be fine. Now I know there is another ten miles in there if something goes wrong. I hope I never have to use it again though.

21 September 2009

Heater power consumption at lowest setting

One hour twenty five minutes of only heater use with lowest fan and lowest heat setting consumed 4% of charge. The cabin temperature went from 47 degrees F to 64.

19 September 2009

Headlight power consumption

Four hours of only headlights on consumed 3% of charge.

I don't think we need to worry about headlights reducing the range noticeably.

Heater power consumption

Running the fan at its lowest speed with the heater at maximum for 1:55 drew the charge meter down 9%.  I don't expect to need max heat often, so I suspect I'll have enough range this winter.  My drive is typically around 1:35, and I have often preheated my cars in the morning during winter with a 900 watt automotive electric heater.  So I probably won't need heat the whole drive.

I took the measurements this morning with the car fully charged, windows open and in the garage.  Ambient temperature in the garage started at 62 degrees F, same as cabin temperature.  After the one hour and 55 minute test, the ambient temperature read 65 and the cabin was 79.

Mini announced a while back that there are some extra high power chargers available for lessees to install at work, now that all the high power chargers have been installed at the homes of  lessees.  I use the low power portable charger at work and have always had a comfortable margin of range for my 3+ hour commute, even in the hot weather where I was running the AC a lot.  But I don't know about the winter when aerodynamic resistance increases, rolling resistance increases, batteries get "stiff" and the heater is on.

At this rate of heater power consumption, I'm not worried.  But it will be nice if they grant me a second charger.  But if they don't, I will deal with it.  I am driving the Mini E this winter, whatever it takes.  I expect it will not be a problem, since everything else has performed as expected or better.

I tried making measurements a couple weeks back using the "Amp Hours per 100 miles" reading on the dash board.  There is too much filtering however, so I could not get numbers that looked trustworthy.  My method was to zero all the gauges, coast in neutral down a small hill for 0.1 miles and then run the heater or AC for ten minutes.  If it worked, it would have given a result in less time.  I'll make some more readings with the longer method described at the beginning, but at different heater settings and post them later.

03 September 2009

The monsoon is over

A couple weeks back we had some very wet weather again in New Jersey.  I recall reports of seven inches in one day in my county.  I was out driving #458 in some of the heaviest rain on the weekend without any problems.  I admit it is a curious feeling to pull in the garage out of rain so hard that visibility is down to a few car lengths, and then plug into a charging box that puts out 16 horsepower at 240 volts.  Again, no problem.  Big grin on my face.

(You know, it takes about as much time to plug in this car at home as it does to plug in my mobile phone, which I also do when I get home.  But I never spend any time at the gas station.  Another big grin.)

Then on the following Monday it was still raining and I went to work on the low roads along the Delaware river again.  Lots of big puddles.  Not a single problem.  Even when I hit puddles too fast that were bigger than I thought.

I know I sound like a stuck record but we really like this car.  I hope they hurry up and put something like it up for sale.  I cannot imagine a Nissan being this  nice.  But we won't ever buy a piston car again if there is anything close to this available.

01 September 2009

109.4 mile average range

I now have data on thirty trips to work where I started at 100% charge. (Click on the title of this posting to see the spreadsheet if you want the details.) Most of these trips were about 60 miles, mostly not on the freeway and averaging just below 40 mph with the stop signs and lights. A few included some freeway travel, but the best I can do with out going well out of my way is about half on the freeway.

The average of trip distance plus estimated remaining miles upon arriving at work is 109.4 miles. This is for mid June through August traveling in New Jersey and Pennsylvania. Some use of AC, some not, for that level of detail see the log spreadsheet.

For those who have not seen the display in the Mini E dash board, the photo at the top of my blog's main page shows the best estimated range I have achieved. It takes a couple cycles of driving at average speeds in the low 30 mph region for the estimate to creep up to that 140+ mile level. But I can reliably exceed 120 miles on one charge just by driving gently. I usually don't, but I can at any time.

Other bloggers have said they checked range when using "hyper-mile" techniques but only for 10 miles or so. The only accurate way is to start at 100% charge and hyper-mile until you reach zero. Or hyper-mile for well over a hundred miles on several charge cycles and then the estimated range reflects how you have been driving. You can't spend most of your time as a "lead foot" and then hyper-mile for a short distance and expect the averaging algorithms to catch up that quickly. The estimates would bounce all over the place if the filtering time constant were that short.

30 August 2009

Big Ears?

I have been experimenting with a lot of different routes to commute to work. While I have managed to cut a couple miles from my trip, I have also gotten some evidence about how much quieter an electric car is.

Not that much from the outside at speed.

I often I take back roads to work through Bucks county in Pennsylvania. There are a fair number of people out walking their dogs, jogging, or just walking. And guess what?

They all hear me coming. Probably from just as far away as if I were in a piston powered car.

Don’t get me wrong, the Mini E is much quieter, especially on the inside, especially if the windows are closed, and especially when accelerating or when moving really slowly (which does not make much tire noise).

But a lot of modern cars are fairly quiet these days when cruising at light throttle. And tire noise at speed is not going to change much based on the motive power source. I suspect that people who are facing away from me are hearing my tire noise when they walk to the edge of the road long before I get close. These are not high speed roads, usually 35 to 40 mph. Maybe 45 tops, some 25.

And the Mini E is not completely quiet at very low speed either, there is a whirring sound when under power even at a fraction of one mile per hour. I suspect it might be the cooling fan, maybe someone more familiar with AC Propulsion’s system can comment. I wonder if this fan noise (or whatever it is) is audible to the average pedestrian. On the other hand, if you don’t touch the throttle, there is no whirring noise below one mph. Although the battery cooling fan always seems to run, though more quietly in the cooler weather now.

22 August 2009

Constant speed versus constant fuel?

Accelerator pedal position in the Mini E is very nearly constant when cruising. It might be close to what engineers would call a constant speed control. By contrast, my foot moves a lot when driving a piston powered car in the hills at steady speed. Perhaps the accelerator pedal in a piston car is closer to a constant fuel rate per stroke, and then the vehicle speed varies widely with engine speed, terrain, gear selection, wind, etc. if the pedal does not move.

I have commented to friends about how easy the Mini E is to drive because of the nearly stationary position of my right foot, but I had not mentioned it in this blog until now. Well, last week when my wife was driving she observed that the Mini E brought to mind that old Irish verse "May the road rise to meet you". It never really made any sense to her and maybe it is a bad literal translation but that fact that the car goes up hills so easily without the driver even having to press the pedal any harder brought the verse to mind.

(I'm starting to get slightly worried that my wife likes this car more than she likes me. The law of unintended consequences is always lurking. Perhaps I am not as easy to get along with as the Mini E. Ha ha. Maybe I should learn from my car.)

I have paid very close attention and when I hold my foot as steady as I can, the Mini E does slow slightly on up hills and speed up slightly on down hills. But only slightly and much less than any other car. I missed not having cruise control at first, but figured it was one of those features that they just did not get to in time. Every prototype project has some features that don't get done in time. But with this car, you hardly miss cruise control.

14 August 2009

There is a bounce at the bottom of the charge gauge

Since a Mini E engineer encouraged me not to hesitate to run the batteries all the way down, I have been watching for an opportunity to do so. The charge estimation algorithms have been very reliable and my range awareness has become quite comfortable. A couple days ago I had the chance to go for zero.

On the way home from work, the charge gauge hit zero at about 5 miles from home. No sweat, everything kept moving right along. I was not on the freeway (I rarely am) and I was expecting some sort of limited road speed but nope, I was driving as usual. Then the fun part: I came to a stop light and while waiting, the gauge crept up a few %. Drive on, it goes back to zero, a downhill, and it creeps up a couple %. This kept going all the way home. It never went negative and when I parked at home and started scribbling down all the numbers from the display that you can find in my logs, it crept up to 3% before I plugged in.

This reminds me a bit of the absolute value of the SINC function, for any of you math geeks out there.  Of course at some point the charge gauge will droop into the negative range but I'll have to push it harder to get there. And I don't care for fast driving, so we'll have to wait until the next time that I'm late for a 7 AM meeting and HAVE to take the freeway to work.  The freeway only saves me a few minutes, but it is many more miles and leaves me at low charge on the way home.

The bottom line is that the Mini E range is probably better than most of us drivers of it realize. And it is not at all like the sudden death overtime of driving a piston car burning "Satan's saliva" (petroleum that is). When you get too low on liquid fuel, your car suddenly stops. The Mini E might slow down, but not at all suddenly. Maybe it is more like a horse when it gets tired. But Mini E 458 didn't even slow down, it just bounced off the trampoline at the bottom of the charge gauge.

If I may digress, I am very suspicious of the talk about the "A" word regarding range in electric cars, and I would really like to see us proponents stop repeating it. Keep in mind that there is always a propaganda machine at work trying to undermine any alternatives to petroleum. Economics 101 says that without alternatives, there is no downward pressure on prices. Petroleum has had a monopoly in transport fuels for a long time, and they will say anything to keep it. So don't repeat the "A" word. Nissan was very smart to use the term range awareness, which I have chosen to follow.

You can probably remember a time when you were young and ran out of gas, right? (Maybe not so young.) Most of use have not done that since. Well, you probably had some anxiety when that happened and ever since you paid attention to the gauges and gas stations and you have been sanguine about your range. There is not much different with an electric car except that if you do run out of charge, you get warning and you slow down gradually. And there are literally about a billion places you can plug in your car if you have the social skills to ask. I have plugged in at a super market, a small local grocery, at work every day, and I have spotted lots of retail locations with outdoor outlets where I could ask if I ran short. Sure it charges slowly at 120 volts. But lets drop the "A" word, OK? Don't play into the hands of the petroleum monopoly.

11 August 2009

80% charging efficiency at highest rate, 60% at lowest

Today I turned off every circuit breaker except for the smoke detectors and the clock radio, then recorded the power company watt hour meter. I read 14% charge remaining when I plugged in the car, and took another reading when the charge rate slowed down at 98% and we really wanted to turn on the central AC again.

I read total power used as 29.3 kilowatt hours for adding 84% charge. By the way this took 2 hours 32 minutes at 50 amps. Sorry, I did not get a precise voltage reading. So:

29.3 / 0.84 = 34.88 KwHr needed to charge from 0% to 100% by extrapolation.

The Mini E spec sheet says usable battery capacity is about 28 KwHr. If we define charging efficiency as usable energy available after charging divided by energy input while charging, I get:

28 / 34.88 = 0.8 or 80% efficiency.

This is very good. I did a similar measurement long ago with the 120 volt charging cable when that was all I had and got a number closer to 60%, presumably due to the fans running just as hard but being a higher fraction of the available charging power.

The 2.9 hour charge time given for the highest charge rate seems to be quite accurate for 0% to 100% charge. However, the 23.6 hour charge time given for the low rate 120 volt charger seems to correspond to charging from 30% (when the first low battery alarm comes on) to 100% by my measurements. I extrapolate to about 37.5 hours for charging from 0% to 100% with the 120 volt box. Of course, this would depend on ambient temperature since that can affect fan speed. I'll meaasure again when it cools down in the autumn. The high rate charge time might be less affected by temperature between 40 and 100 F.

The real point of all this is trying to estimate how much of an effect terrain and start stop driving have on range versus the effect of speed. Assuming that regenerative braking is as or more efficient than the high rate charger, I am guessing that 80% efficiency goes a long way towards removing the effect of hills and start stop driving. High speed might be the bigger cost to range.

And by the way, I once figured the max regen rate works out to about 20 Kw, which is much higher than the 12 Kw max charge rate for the wall box. So efficiency might be above 80% for regenerative braking.

I had thought I should strive not to go below 30% battery charge since that is where the low battery warnings start. But one of the Mini engineers at a Mini E social event encouraged me to run it as low as I want, even into the negative area. He insisted the battery was fully protected and I would only lose speed at very low charge levels. I usually get home in the 20% vicinity. You can see the details in my trip logs. (Click on the title line of the oldest posting.) I have noticed limited acceleration when passing when I am below 20% but never any sense of a speed limit yet. Some day I'll get the nerve to get down to 'zero' charge or below. Not this week.

10 August 2009

Minor EMC issue

At 3600 miles, I finally found a complaint, however minor.

The rear window defogger can wipe out radio reception. Specifically, driving from Princeton to Hopewell NJ and listening to 88.1 or 90.9 works only when the rear window defogger is off.

I have not run into this in other cars, although a colleague with long automotive experience has.

If this is the worst of the problems, it only reinforces what an excellent job they have done on this prototype vehicle.

And Electro Magnetic Compatibility issues like this can be pretty easy to fix. Or not. I have seen issues that take down the entire CAN communication bus, now that was serious. But there was a very simple fix.

I have other comments about the radio but I want to limit this blog to observations that are specific to the electric only version, and I suspect the radio is common with the piston versions of the Mini. Plus, I have not read the manual for the radio yet and I don't want to make a fool out of myself. Yet.

UPDATE:  It seems the EMI from the defroster is intermittent, maybe there is a loose wire and not a design issue.  This is not worth a trip to the dealer, certainly not in warm weather.  The occassional fog lately is something I can live with without using the defroster.  When we go on vacation I'll drop it off for them to look into.

08 August 2009

Qualitative Comments

I have to digress from the theme of this blog and move from the quantitative to the qualitative.

The reason this car is such a wonderful ride is the gestalt of less noise, less vibration, less smell, less heat, and less guilt about the fuel source.  Being someone who occasionally falls into the trap of 'road rage', I can testify that driving this electric car has a salutary effect that mollifies the tendency towards aggression and makes it easy to take one's time.

I do not expect those that have to drive in NYC or LA to experience this effect, with the over riding pressure of those environments.  But combined with the opportunity to drive on county roads with low traffic, this car has convinced me that I am never going back to piston power if I can avoid it.  Do not misunderstand, I loved driving on biodiesel for years and in the short term it might even be better environmentally than the nuclear based electric power here in New Jersey.  But it does not have the multidimensional luxury of electric power.  And of course electric power can move to solar and wind, I just don't have those options immediately.  Soon maybe.

I have heard that when the first flush toilet was installed in the White House, it was a novelty.  Most people had outhouses, which got the job done but they were uncomfortable, stinky, not so healthy and not so good for the environment.

Today, electric cars are a novelty.  Piston cars cars get the job done but they are uncomfortable, stinky, not so healthy and not so good for the environment nor for geopolitical stability.

OK, to take the metaphor to the limit, I would be in a hurry if I were still driving around in the automotive equivalent of an outhouse.  But I'm not.  I'm driving a Mini E.  And I love it.  I admit that in the best of all possible worlds we would not need cars.  At the moment I do need a car, and I'll take the metaphorical equivalent of a flush toilet over an outhouse, even if it is more expensive.

My wife was skeptical about this car at first, mostly due to the cost.  But she realized that with my ridiculously long commute, there was value in reducing my driving stress.  She is hooked now too.  Though my wife NEVER liked to drive, now she grabs the key fob and heads for the driver's door of the Mini E, while I follow to the passenger's door.  And she has started to complain about her car.

The second time we came home from church in the Mini E, my wife said "When the lease runs out on this car, it is going to be very sad".  I knew she was hooked.

I have to get a windows sticker made, saying "Pistons?  We don't need no stinking pistons!"

07 August 2009

Battery temperature

I do not drive much on the freeway, but I had to yesterday. After charging the Mini E all day at work as usual, the battery temperature was 104 degrees F when I left. I have sun shades in the windshield and on one side window, but it is still fairly warm in the car even with the fan running while the batteries charge.

On the freeway I was driving rather aggressively, and saw the battery temperature peak at 109 degrees F about three quarters of the way through my 68 mile trip. Now this is fine, the car ran perfectly, the AC is very strong, range is great. But 109 degrees is close to what I recall as the limit for regenerative braking to function.

So I question the wisdom in the owners manual of recommending that the windows always be fully closed when the car is parked. If I did not have the car plugged in and charging, it would be much hotter in there without the fan. Has anyone else gotten into a high enough temperature that they lost regen? The only blog I have read about loss of regen was related to problem that was repaired.

So I leave the windows slightly open if there is no rain in the forecast. And if rain is expected, it is usually cloudy enough that the car stays cooler even with the windows closed fully.

But I would like to know from Mini if the fan always exhausts interior air to the outside to cool the batteries? Would it work better to reverse the fan when the inside of the car is hotter than the outside? Can the battery fan reverse in winter to heat the cabin when the batteries get hot? (Maybe the batteries don't get that hot in winter.)

It is rare for me to drive aggressively, so I don't think I'll see these high battery temperatures again. I suspect that Mini or BMW will go to a liquid cooled battery when they come out with a production electric car. But they seem to have done a very nice job for a prototype.

And I love the fact that the car stays as cool as it does parked in the sun when it is plugged in. Too bad the AC won't run when it is charging but it is hardly needed in my experience. Maybe I should get in interior thermometer and put some more numbers in this post...

05 August 2009

Portable charger not completely water proof

Several weeks back there was a heavy rain at work before I left for home. The 120 volt charger was lying flat on the concrete, face up and the car was still charging when I unplugged it. When I got home, the 120 volt charger would not start, both red LEDs were blinking which means an internal fault. (This was before the wall mounted charger was installed.) 
Knowing what happened, I unplugged the charger, carefully opened the case, and poured out the water. I dried it with a hair dryer set on low for about ten minutes and it was fine. 

The gasket and grommets look perfect, I don't know where the leak is. Normally I hang the charger from the strap when it looks like rain, but this day I did not.

One of the GFI outlets at work that I use to charge the car started tripping a few weeks ago. I thought at first that one of the guys was pulling a practical joke by pressing the 'test" button on the GFI, since I had charged at that outlet many times with no trouble. But now I suspect that moisture in the yellow box caused the external GFI to trip before it got so bad that the yellow box decided it had an internal problem. That outlet seems to be working again now that I dried out the yellow box. 

In the photo you can also see the meter I use. I have to pay for the electricity I consume at work. The extension cord is 12 gauge, with screw terminal connectors. It does not get warm. The owner's manual warns not to use extension cords, but this one is sufficiently over rated. Most molded connectors on extension cords from the hardware store will over heat after a few hours at 12 amps, so I agree in principal with the owner's manual. But the outdoor outlets at work have spring loaded covers and I cannot get the power meter in directly, so I use this heavy extension cord.

02 August 2009

Detailed trip logs

Central New Jersey might be the last location to get wall chargers installed for the Mini E. Something about the inspectors being fussy here. For various reasons I delayed blogging about Mini E #458 until my 50 amp charger was installed, which happened two days ago.

So far I have been driving my 120 mile round trip commute only 3 days a week due to the long charge time at 120 volts. We also drive on the weekend but usually less than 100 miles total. With the big charger I should be putting 3000 miles per month on the car.

I had my first problem last weekend when the car refused to charge. I still had only the "baby" charger at the time. It still drove fine, so I dropped it at the dealer on Monday night where it also refused to charge with their "adult" 50 amp charger. They checked it in Tuesday morning, sounds like the "flying doctor" checked it out on Wednesday, Thursday it was fixed and Friday we picked it up.

The dealer says I was the first to take delivery in Princeton, and the first to bring it in for the 3000 mile check up. If I had not had the charging problem, I would have been over 3000 when I went in for service, instead of just under 3000 miles on the odometer.

I have never seen a car as anything more than a mobile appliance. Much the same for my wife. We used biodiesel in an old Mercedes for 4 years before now, and that was interesting and a little annoying. The Mini E is the first car either of us has been impressed with. Of course it is mostly about the fuel, but the car is well executed in most respects. This is the future.

My trip log is linked, click on the title of this post "Detailed Trip Logs" above.  It will open a Google Spreadsheet.  You can see that I don't always get a range over 140 miles, but I get a very dependable 120 mile range when I'm not in a hurry. Analysis and summary to come in later posts.