Parasitic Draw on RV?
I am getting ready to add a small solar system to the top of my 5er to keep the batteries topped off when we leave the camper at the lake for extended periods. My wife and I generally pull the camper ...
Forum Discussion
pianotuna wrote:
Just remember that if the voltage to the controller is doubled, the voltage drop is reduced by 50%. Be aware that losses in the MPPT controller rise with the input voltage. Worst case is about 96%.
I do harvest 17 amps from a 256 watt flat fixed installation, with panels in series/parallel giving a controller input voltage of 33. My line losses between panels and controller are on the order of 1%. They would be much higher if I had gone all parallel.
Trying to stay 12v here for both PWM and MPPT to not confuse the voltage drop comparison and the whole thing about wire gauge with 24 vs 12.
On the "12v" controller to array wires, with PWM you have battery voltage (12-15v) and with MPPT you would have 17v Vmp during the Bulk stage, so only a little higher voltage with MPPT there.
The amps on that wire pair would be the 25 amps with PWM at Isc value, and Imp with MPPT being a little less in amps.
