FVEAA Forums

EV Technology => Batteries => Topic started by: ted.lowe on July 21, 2014, 09:59:31 PM

Title: Battery Heaters and Temperature Control
Post by: ted.lowe on July 21, 2014, 09:59:31 PM

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.pdf (http://www.fveaa.org/fb/calb-ca-cell-specs_384.pdf)

Many 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/ (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+22100 (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+22100)

These types of resistive heaters contain nichrome wire that generates the heat when powered by 120V AC.  http://en.wikipedia.org/wiki/Nichrome (http://en.wikipedia.org/wiki/Nichrome)

Another 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.

Title: Re: Battery Heaters and Temperature Control
Post by: michael.willuweit on July 22, 2014, 12:58:07 AM

Thanks for posting Ted.
Take a look at this page by Lee Hart. He takes the wire off the blanket and makes a custom sized foil for the specific battery box.

It's about 3/4 of the way down the page
http://www.sunrise-ev.com/LeesEVs.htm

Title: Re: Battery Heaters and Temperature Control
Post by: michael.willuweit on July 22, 2014, 01:30:17 AM

Here is a really cool temp display and controller.

http://www.lightobject.com/JLD612-Dual-Display-PID-Temperature-Controller-P43.aspx

they have quite a few temp probes and Thermocouples, here is the probe EVTV sells with it:
http://www.lightobject.com/Premium-Stainless-Steel-Waterproof-PT100-RTD-Temperature-Sensor-Probe-Threaded-P681.aspx


I guess I would need 3 of these for three battery boxes?