My original plan was to place the battery chargers under the hood, next to the batteries. It turned out that waterproof fanless chargers were very highly priced and thus did not fit in this low cost project.
The chargers that were chosen for the project are fan cooled and ment to be used indoors so they had to be mounted in the cabin. The most suitable place for them was found from the front passengers feet space.
The heater assembly was finished by adding a second aluminum plate on top of the power resistors using a clamp made from steel. The five 2.7ohm resistors were connected in parallel using 4mm^2 wire. After testing that each resistor and temperature switch worked the heater assembly was painted using black exhaust paint that withstands temperatures up to 650C.
The heater assembly was then mounted on top of the air vents that blow air to the windshield. The heater assembly is only 30mm high so it does not block visibility much. After it was painted black it fits quite well into corollas interiors. I hope there is now enough heat available to keep the windshield clear of fog.
