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Re: (ET) Found the problem with the charger



Hello David
 
Small world I am an OSU solar car sponsor. Here is our link.
 
 
My business refinished the car and supplied the A123 batteries. A123 batteries are LiFePo4 and do not have as high of energy density as the OSU solar team wanted. So for the next years race they planned to use a non safe lithium chemistry. I warned them that the risks were very great of starting a fire that can not be put out. Sadly the solar car was destroyed and the driver got out burned badly but just in the nick of time.
 
So to be clear this OSU solar car was not using A123 cells or LiFePo4 when the pack caught on fire.
 
By the way I have never sold A123 cells but at the time I did have 6000 cells so I loaned them as many as they needed. This was in the solar car in the race the year before the fire.
 
The LifePo4 chemistry is extremely safe. If you over charge them the only thing you will do is destroy them. If you vastly over charge them the cells will just expand and come apart but no fire.
 
I have been following the development of LiFePo4 for years. At first the good cells like the A123 were too expensive and the lower cost cells had quality issues. Over the years the gap has closed and now LiFePo4 is far more cost effective then lead. In the last few months I have started selling CALB cells as I feel they are the best buy on the market. There is very little markup and I have not even covered my cost but I have moved a lot of cells.
 
Anyway we just refinished the new OSU solar car. The good news is A123 heard about their fire and is now sponsoring them with safe LiFePo4 batteries.
 
My business is collision repair and in the same location for 27 years. I have been driving an EV for almost 100 percent of my driving for the last 8 years and have over 100,000 miles. As soon as the new J1772 charging stations came out I put one at our business where others can charge 365 days a year at no charge. My goal is to help others drive electric. I am not motivated by profit but to help reduce our dependence on imported oil.
 
Don Blazer
 
 
 
In a message dated 7/15/2012 4:42:09 P.M. Pacific Daylight Time, etpost drmm net writes:
Lithium: I am far from an expert here, but from what I hear, overcharging
can set the battery on fire!  Some species of lithium batteries have
flammable electrolyte, which makes things worse.  A lithium fire burns hot
and is hard to put out. 

http://www.gazettetimes.com/news/local/article_803a17e6-afd8-11e0-bedd-
001cc4c03286.html

http://tinyurl.com/czphnfj

Lithium batteries have a heaping helping of energy in a small, somewhat
unstable package.  They deserve and require serious respect. 

You do not want to overcharge a lithium battery.  You need a BMS that can
shut off your charger when it's full, AND a safety backup that can shut off
the charger if the BMS fails or gets confused and doesn't do it.

There are applications where lithum makes sense - where you need maximum
capacity and minimum weight.  It's hard for me to see how that applies to an
ET in normal service, but maybe I'm missing something.

Lithium makes sense for a push mower and I will probably head down that road
sometime this summer or next.  However, I have no interest whatsoever in
converting either of my ETs to lithium batteries.


David Roden - Akron, Ohio, USA