Battery heating for EV efficiency

[bennelson]

http://www.youtube.com/watch?v=Lm5IATVw3WI

While I built a battery warmer for the Electro-Metro a while back, I never got it installed.

There was some sort of a problem that was setting off the GFI on my charging power outlet AND the GFI in the car.

I took the cover off the warmer, fixed the problem, and installed the warmer in the car.

Running the warmer for an hour or so seemed to bring the batteries up to "Not Cold" temperatures, which is all I am trying to do - just get the batteries somewhere between 50 and 70 degrees F.

I will still need to experiment to find out what the ideal run-times for the battery warmer are at various temperatures.

Since the battery box is INSIDE the car, any heat escaping from the battery box should help to heat the cabin (at least a tiny bit!)

[Rokeby]

orange4boy recently posted up on my similar thread at PRIUSchat.
Perhaps my reply has some value for this thread:

Originally Posted by orange4boy

...There is a tiny bit of room under the case but the whole pack would
have to be lifted a bit and some bolt holes elongated for that to work.
Might as well put it under the batteries if possible. Christ from EM has
suggested waterbed heater pads as they have a thermostat and are
thin.

FWIW, here is my list of thinnish heating products most likely to work
either under the whole battery box, or between the box and the HV
battery itself -- some of them are pretty "out there."

Self Adhesive Engine, Oil, Block Pre-Heating Pad

Wolverine Engine Oil Heaters - Products

ClearMirror® : The original fog free bathroom mirror defogger - From $69

Electric Foot of the Bed Warmer - Stops Cold Feet!: CozyWinters

http://www.comfortheat.com/files/product_ffm.pdf

Thermocouples, Coil Heaters, Mica Heater Bands, Ceramic Heaters
The “FuzzyLogic” Logic Temperature Controllers warrant a look, but are
probably prohibitively expensive.

These two items are 12v, so would require a 120vAC to 12vDC transformer.
At any rate they are too neat not to pass along:

OEM Products, 12 Volt Heating, Carbon Fiber Dual Temp Waterproof Single Pad Seat Heater Kit

This for blowing hot air through the back seat HV battery inlet vent:

Moose Racing UTV Cab Heater - - Motorcycle Superstore