Solar Help
I have an older Class B motorhome and have been thinking about solar. I can boondock now for 2 days before I have to recharge my 125ah battery. The only thing that draws power is the 12V fridge whic...
Forum Discussion
PT is confusing matters by not explaining. Panel voltage is the same as battery voltage with a 12v system. As battery voltage rises the spread between battery voltage and panel Voc spec voltage shrinks, reducing amps.
With lower battery voltage (and so panel voltage) the spread is large and amps can flow.
However, you don't want those lower voltage panels they had for a while with only 32 cells that were "15v" instead of "17v" like 36 cell panels. those lower voltage panels could not charge RV batteries to 14v because the spread was too small between 14 and 15 so they went to 17 to get more spread so battery voltage could rise to where it needs to go.
BTW, with a B and roof real estate "issues" you might be better off with 24v panels and MPPT for the amps you can get in that space, but it will co$t you for that MPPT. OTOH a B can't carry many batteries, so you don't need that many amps perhaps.
With lower battery voltage (and so panel voltage) the spread is large and amps can flow.
However, you don't want those lower voltage panels they had for a while with only 32 cells that were "15v" instead of "17v" like 36 cell panels. those lower voltage panels could not charge RV batteries to 14v because the spread was too small between 14 and 15 so they went to 17 to get more spread so battery voltage could rise to where it needs to go.
BTW, with a B and roof real estate "issues" you might be better off with 24v panels and MPPT for the amps you can get in that space, but it will co$t you for that MPPT. OTOH a B can't carry many batteries, so you don't need that many amps perhaps.
