12v MPPT and 24v MPPT vs 24v PWM Test
Got a chance to try out comparing amps to the battery using MPPT vs PWM on a 24v battery bank and comparing those with the usual MPPT on 12v with my 230w panel. The bank is four 6s, so it was easy ...
Forum Discussion
jrnymn7 wrote:
Even with 12v to 12v mppt being more efficient, wouldn't 24v to 12v mppt yield more in the way of Amps to the battery? And would it depend on whether the 24v is from an actual 24v panel, or two 12's in series?
My answer to that first question is right there in the OP assuming 24-24 is like 12-12
The second question would depend on any wiring losses from the parallel links which you don't have with a single panel? I don't know any reason why they should be different otherwise. (Except in partial shade maybe)
What I find most interesting is that higher Isc proportion in the single 230w than in the 130w, which ought to make the single 230w with PWM (so it would have to be on a 24v battery) do more amps than two 115w panels in series with PWM on a 24v battery.
You can't really compare panels by Vmp ratio to Rated Watts to see what the resulting Imp would be. Imp has little to do with amps to the battery with MPPT. all Imp does is make up part of the watts for the INPUT watts to the controller. Then you get OUTPUT watts.
Now you still have to divide that by the battery voltage to see what amps you get to the battery. It is completely different from how you get amps to the battery using PWM, which just uses panel amps right from the panel.
