And that helps ventilate a battery compartment? What you did would have no effect whatsoever on a direct panel driven fan. A 48 volt fan can be driven at 8 volts the result being a very slow fan to match 0.0 charging amps. It really isn't important unless open circuit panel voltage exceeds the voltage rating of the fan. And if fan speed is too low a higher ma fan can be used. An overwhelming majority of NORMAL charging by-product is pure hydrogen that wants to fly straight up at high speed. If PWM is coupled to an excessively noisy fan the fan speed can be discerned when pulses vary.
