This is a new thread to discuss an old topic, namely, how to keep batteries in the proper temperature range in the winter months in the Chicago area.
Mike Willuweit is on this battery heater stage with his Porsche project and the Dakota project will similarly need battery heating.
The CALB CA cells both Mike (100AH) and the Dakota (180AH) are using specify that
charging must be done above freezing!Here's a PDF with all the CALB CA cell specs:
http://www.fveaa.org/fb/calb-ca-cell-specs_384.pdfMany years ago i documented a good (proven) and affordable process for doing battery heating i learned from an experienced Canadian (think cold) EVer named Rick Lane. Here's the gallery documenting the process:
http://www.fveaa.org/members/tedlowe/winterizingEV/The process uses off-the-shelf battery heater blankets, re-purposed to fit under EV batteries. Mike shared this link to such a heater, eg,
http://www.amazon.com/Kats-22100-Watt-Battery-Thermal/dp/B000I8VKZ8/ref=sr_1_1?ie=UTF8&qid=1405978985&sr=8-1&keywords=kat%27s+22100These types of resistive heaters contain nichrome wire that generates the heat when powered by 120V AC.
http://en.wikipedia.org/wiki/NichromeAnother possibility instead of using re-purposed blankets it is to buy a spool of the appropriate nichrome wire. More later on this.
i've long wanted to build a cheap (yet flexible) temperature measuring and control system. More later on this.