Maybe I should change the circuit in a way that I first try to use only the fan which is mounted at the peltier (inside the closed battery case) to cool the battery and add the active peltier cooling only if this pure fan cooling will not be enough to keep it cool. Like a 2 stage cooling:
1st stage: inside fan only
2nd stage: inside fan plus peltier and outside fan
In 1st stage the energy consumption would be very low, just the inside fan. The 70 watt peltier will only be used when 2nd stage will be active.
The problem with this approach is, in 1st stage I usually need an open system to let outside air in and for 2nd stage, a closed system with recirculate air would be better.
Until now, my design is a closed system with just recirculate air (for heating and cooling).
Btw. I only plan ONE peltier element with 6 amps (70 watts) - not two.
