Folks,
I have an off-grid installation with 12 each of 18 VDC Solar PV panels producing 100Watts in direct sunlight (in the American Southwest, if that matters to you). My battery system is 4 each of 6 volt Duracell Ultra batteries which are wired series-parallel (producing 12VDC). I already own the MPPT 150/85 MCA, the feed wires are run, I have some 4-to-1 parallel cables which I was considering hooking 3 banks of 4 panels in parallel (there are 3 MCA input pairs on the unit)...
I believe that will produce 18-21V at about 22 amps per pair... which should be more than enough in theory to do what I need it to do if I understand my requirements correctly.
My question to you: Is there a more efficient way to charge these batteries with the current setup I have? I.E. - Should I do 6 banks of 2 panels in series (~36V), then parallel 2-to-1 down to the 3 inputs with 24V charging?
What is the best way to handle this considering my low wattage panels and the multitude of them?
(Panel Specs)
12 of the following panels -
Specification:
Optimal power [Pmax]: 100W(±5%)
Working voltage [Vmp]: 18V
Working current [Imp]: 5.62A
Short circuit current [Isc]: 5.97A
Open circuit voltage [Voc]: 21.6V
Dimensions: 105 x 54 x 0.25 cm/41.3 x 21.3 x 0.09 inch
Net weight: 2.6kg/5.73 lbs.
Working Temperature:-40~+85℃