Electric car conversion heating and ventilation?

A friend and I are about 95 % complete with converting a Porsche 914 to full electric. Throughout this time I had been pondering how to have some sort of heating system installed without it sucking the juice right out of the auxiliary battery. I live in San Francisco and we have a lot of fog so a defrost system will be a must.

I have also decided to completely redo the fan ventillation system as the stock one is old and antiquated.

Any thoughts or feed back would be greatly appreciated.


Most are replacing the heater core with a ceramic heater powered by the traction pack voltage. Very little change in range.