I have a 24v battery house bank and am looking to install Solar panels for the first time. Bearing in mind W/V = I, then on a 24v system one will need a panel twice the Watts as one needs on a 12v system in order to produce the same Amps : A 200w panel/24v = 8.33 amps, A 100w panel/12v = 8.33 amps : GIVEN THE SAME SUNSHINE/TEMPERATURE etc.
Is that correct ??
Since the object of the whole excercise is to recharge the batteries, i.e. put back into them as much Amps as possible (as efficiently as possible), does it not make sense to have a 12v panel connected to an MPPT charge controller which then 'steps up' the voltage to say about 28v, which necessary to recharge the 24v house bank ...?
I have been told so many conflicting things e.g. to recharge a 24v battery bank one must use 24v panels and to recharge a 12v system one must use 12v panels.
But others have said there is an MPPT controller which will do the 'step up' (12v stepped up to 24v).
Given that 12v panels are a lot cheaper than 24v panels ...and if W/V = Amps, one only needs half the Wattage panel for 12v as one would need for 24v to get the same amps out.
what about using two separate 12v , 100w panels connected sparately to two MPPT controllers which then all connected to the house bank.?