19 April 2012

If you are in Chicago...


This is what Green Wheels Chicago looks like. 
1540 North Western Avenue, Chicago, IL 60622 
Not sure if that is the view from the street.  
Their prices for the Think mentioned in my previous post include shipping.
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5 comments:

  1. AnonymousApril 22, 2012 at 1:54 PM

    Jim,

    Ive been trying to find technical information about the 2011 think I bought from chicago (deliver in about a week.) I have been driving lifepo4 evs for 5 years now (modifed by me solcetria forces) ask me about the care and feeding of thundersky or calb cells and im a walking technical manual. However these cells (on the think) are only talked about generally. IE wider temp range for operation and charging but not what that range is. From what I gather there is a bms at the cell level but nothing about how it functions. I wonder do you know (or perhaps have a tech ref) about the batteries and bms?

    What Id really like to know is general care and feeding of the enerdel cell.

    Is there a battery heater (ie should we leave them plugged in during the winter and does it run on 120 and 240 or just 240 (like my force battery heater does?)

    Does the bms shunt or shuttle charge to ballance cells when needed (ie should we leave it plugged in all the time or once a week or once a month balancing etc?

    Im sure Th!nk has made a plug and forget system but I like to know what is going on under the hood so to speak.

    Also could you go over any other gotcha's you learned over the last year that may not be in the blog would help too.
    Thanks
    Dex

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  2. Jim McLApril 22, 2012 at 2:23 PM

    Dex, no battery heater but it will charge down to -15 F if I recall. (The Mini would stop around plus 20 or so.)

    I assume there is cell balancing like all modern EV Battery Management Systems. But I do not have any details. I have been in the Ener Del factory outside Indianapolis, but only to test drive the car last year.

    These are automotive grade cells, unlike the laptop cells in many other cars. Originally developed by Delphi before being spun off. So while my volume of technical details is small, my confidence is high.

    I usually limit charging to the 80 to 90% range during the work week to extend life. I regularly charge to 100% on the weekends.

    There might be more on the Norwegian forums, I will check.

    ReplyDelete
  3. AnonymousApril 22, 2012 at 5:39 PM

    Great id appreciate any info. So these cells benefit in cycle life from not being charged fully like most lithium cells. Is there a timer for the charger or do you put a timer on the 110 wallside?

    ReplyDelete
  4. Jim McLApril 22, 2012 at 10:32 PM

    Dex

    No built in timer, I use a mechanical timer. Since the resolution on those mechanical timers is so poor, I tend to mostly charge at 120 volts because being slower, I can set the cut off more accurately. Some day I will set up an electronic timer.

    I was a bit puzzled by your first question until I thought about it. I have not worked with DIY EVs, and I gather that cell balance is an issue. But remember, Ford owned Think for several years and put something over 100 million dollars into it, some say 150 million. What I have heard is that most of that went into the battery management. It shows. The high resolution of the charge gauge is a great asset, I cannot imagine trying to drive a Leaf on long trips with that ten bar display. I suspect Nissan did that on purpose, not to save a couple dollars. It probably helps cover up poor estimation by the Leaf BMS.

    You ask about "gotchas", I really cannot come up with anything that is not trivial or obvious:

    Disadvantages:
    1) More noise than the Mini E, mostly only audible at low speed (the vacuum pump in particular, to a lesser extent the power steering pump and on very hot days the roof panel makes a little noise as it expands when you pull into the sun from being parked in the shade). At high speed, the motor whirr can be annoying if the radio is off. Bothered me at first, I don't notice it anymore.

    2) Think did go bankrupt again, we all know that. But the new owners are VERY well capitalized from what I hear. I am wondering if these clearance prices are a sign that the new models are not far behind.

    3) The down side of these new low prices is that the warranty is shorter. 3 years on everything. On our first Think where we paid almost twice as much, some parts of the warranty ran 8 years if I recall.

    4) Like all EVs that were designed before the 2010 update to J1772, you should unplug or power down the charging box before unplugging the connector. Otherwise it might spark a little, and wear out the connector over time. Tesla roadster and Mini E are the same way. If charging is complete, this does not apply.

    There were some more serious issues with the early European versions of the 5th gen Think in 2008, all fixed before production started here. Heaters and such. And the Zebra battery can be delicate, but it is not available stateside. Of course the Zebra rocks in winter, but it tends to die after accidents.

    Advantages:
    1) Oldest dedicated EV maker on the planet, with 700 ten year old (4th gen) models in daily service in Norway today, many more across Europe. I saw my first Think 11 years ago in Pennsylvania, I have been following them in the news for over 20 years.

    2) Advanced polymer body panels. I loved them in my Saturn also, don't think I would ever buy a tin can car with stamped steel body panels again like the Leaf. The BMW i3 will be carbon fiber, that should do. Lighter. The Smart is plastic, but a bit too small.

    3) The Think has rock solid reliability. We loved the Mini E but it was not reliable. My wife decided to get a second Think partly because I have spent almost zero time on it in 10,000 miles. I put air in the tires. I blog about it. That's it.

    I could go on but it probably belongs in another post.

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  5. AnonymousApril 23, 2012 at 4:59 PM

    Thanks for the list. Nothing aside from the bankruptcy out of the ordinary. Yes balancing is necessary depending on the quality of the pack. I have one very good and one not so good. The not so good one i balance every 6 months or so. The cells are all over the place from 85 AH to 110Ah and different IR as well. Plus with a cell lever bms that takes power from the cells at slightly different rates the bms itself can pull them out of balance over time. If however the cells are very well matched and age the same over time you dont really need a bms for Lifepo4.

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