I purchased 5 24v panels on sale end of last year that were a great deal. They are not made anymore, thus the good deal. Never should have bought an odd number. That being said, this is where I am now.
I have 5 24v RNG-270P panels. I was planning on setting up the panels in series and charging a 24v LiFePO4 battery bank and utilizing a 24v inverter. Max voltage and charging voltage now throwing a wrench in everything. Voc is 38.6, Isc is 9. I could run 4 panels in series/parallel and be at 80v and 18a with a 30amp MPPT, but then I'd have one panel that has no use. Too little voltage to charge the battery bank most of the time if the single panel was connecting to a stand alone MPPT. I could run 3 in series but that would put me over 100v PV input and run into more expensive MPPT chargers. Seems I'm stuck in no mans land. Run 4 panels and it fits right but waste a panel (one panel to MPPT might not have enough V to charge batteries). Run 3 panels in series and 2 panels in series, but need 1 expensive MPPT to have a limit over 100v input. If I mix a 3/2 input in series/parallel to a single MPPT, the voltage will be brought down and I'm left in the same scenario as not connecting a 5th panel.
The cost effective option is to run 4 panels in series/parallel with a 30amp MPPT and keep a spare (wasted) panel. I could use all 5 with a 3 going to one MPPT and 2 going to another if one MPPT was over 150V max input, but that would be expensive.
I'd buy another panel if I could so I could run 3/3 series/parallel.
Wondering if I've covered 'best' options or if there's something I haven't thought of. Attached solar panel output for reference as well.
Thanks-
I have 5 24v RNG-270P panels. I was planning on setting up the panels in series and charging a 24v LiFePO4 battery bank and utilizing a 24v inverter. Max voltage and charging voltage now throwing a wrench in everything. Voc is 38.6, Isc is 9. I could run 4 panels in series/parallel and be at 80v and 18a with a 30amp MPPT, but then I'd have one panel that has no use. Too little voltage to charge the battery bank most of the time if the single panel was connecting to a stand alone MPPT. I could run 3 in series but that would put me over 100v PV input and run into more expensive MPPT chargers. Seems I'm stuck in no mans land. Run 4 panels and it fits right but waste a panel (one panel to MPPT might not have enough V to charge batteries). Run 3 panels in series and 2 panels in series, but need 1 expensive MPPT to have a limit over 100v input. If I mix a 3/2 input in series/parallel to a single MPPT, the voltage will be brought down and I'm left in the same scenario as not connecting a 5th panel.
The cost effective option is to run 4 panels in series/parallel with a 30amp MPPT and keep a spare (wasted) panel. I could use all 5 with a 3 going to one MPPT and 2 going to another if one MPPT was over 150V max input, but that would be expensive.
I'd buy another panel if I could so I could run 3/3 series/parallel.
Wondering if I've covered 'best' options or if there's something I haven't thought of. Attached solar panel output for reference as well.
Thanks-