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.

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