An extended fall season has allowed driving my car till November 29, 2009. Driving and charging every day could maintain the batteries at ~15 to 20 Celcius, despite sub-zero outside temperatures. Skipping a day or two of driving, and the batteries got below 10C, and range would be seriously affected. A heat source in the battery boxes is needed.
As a heat source, my plan is to use the heating wires from automotive battery warmers. These consist of filaments looped and glued on an aluminum foil backed with a fibre insulation and packaged in a sealed bag. Here, I am stripping out the heating elements components from the bags.
To help dissipate the heat across the bottom of the box, the foil will be contact with a thin aluminum sheet (roof flashing, actually).
Here, the aluminum sheets are sized to cover the bottom of the boxes, and the batteries go overtop. hopefully, under the weight of the batteries, the foam will give way and not crush the heater wires. This is front battery box.
The rear battery box.
The heating is controled using a terrarium temperature controller, one for each box.
The long wires for the power and thermocouple permit mounting the temperature display just below the dash.
As a heat source, my plan is to use the heating wires from automotive battery warmers. These consist of filaments looped and glued on an aluminum foil backed with a fibre insulation and packaged in a sealed bag. Here, I am stripping out the heating elements components from the bags.
To help dissipate the heat across the bottom of the box, the foil will be contact with a thin aluminum sheet (roof flashing, actually).
Here, the aluminum sheets are sized to cover the bottom of the boxes, and the batteries go overtop. hopefully, under the weight of the batteries, the foam will give way and not crush the heater wires. This is front battery box.
The rear battery box.
The heating is controled using a terrarium temperature controller, one for each box.
The long wires for the power and thermocouple permit mounting the temperature display just below the dash.
To help have a stable temperature measurement by eliminating drafts, the thermocouple is suspended in the a form doughnut.....
.... which is stuffed in between the middle two batteries.
It takes about 4 hours to get to 20C from 10c
Modifications were made to method of mounting the motor and transmission, to use a cage structure that support points that use the original rubber motor mounts.
The motor-transmission assembly in the car.
Keeping it simple, the spash guard for the motor.....
... installed.
