Which is better - (3) 12v batteries vs (2) 6v batteries

Hi BFL13,

Under heavy loads use all the batteries. It is possible to bank switch, as I isolate my two banks. Charge them separately, or even charge one bank while using the other. This is especially nice when there is some solar energy to be had.

The only potentially safe way to use the heater exhaust that I can think of, is to have double walled tubing acting as an additional heat exchanger/extension exhaust pipe. Possible but pricy.