ok so i live in indiana where freezing will be a concern 4-5 months a year. I have thought of a couple ways to just keep the unit warm enough not to freeze but not get it hot.
First I was wondering about using heat tape like what used in mobile homes to keep the pipes from freezing. It has a couple of advantages. 1st, it uses 7 watts per foot. 2nd, Its waterproof to a point. 3rd, it comes ready to use with a thermostat built in to turn on at 38 degrees f and turn off at 45 degrees f. The only disadvantage would be that it runs 120 volts ac. So I figure I will use an inverter hooked to the battery to only run when the car is not on and then use a trickle charger to keep the battery charged.
Second idea was to use an inline heater installed in the lines of the unit with a pump. I have seen them before in other applications years ago but I don't remember for what and I cant seem to find them now. But also I don't know what the solution would do to the workings of said heat pump.
How do you guys keep the system from freezing though? I don't want to up the electrolyte unless its absolutely necessary because if I understand properly if I up the electrolyte I will also up the amps and cause the cell to heat up correct?