4@12v = 24v

DryCamper11 wrote:
I'm assuming one advantage of 24 volts is reduced inverter current draw. My inverter is only 1200 watts and still draws 100 amps. Is that the main reason to go with higher voltages, or does the availability of higher voltage solar play into the decision?

In my case, both played a role.

Reduced current draw means smaller wire, which is much easier to work with. My previous 12v- T605 setup had 4/0 to the inverter with #1 interconnects. The interconnects could handle the high-current of something like a MW for a minute, maybe, then things would start to heat up. I did not want to wrestle with bigger interconnect wire, so I decided to up things to 24v.

As for the solar, my pre-wired 5er had #10 from the roof to basement, which wasn't going to cut it for 6 panels in parallel. My Outback controller handles up to 150vdc input and charges 12,24,36, 48 and 60v battery banks. Ya hoo.

The little DC converter is a neat little device (around $100) which keeps my house voltage at 12.5.. all the time.

Salvo wrote:
Charge controllers are current limited. A 12V battery system may limit solar to 300W. The same controller in a 24V system is limited to 600W, while a 36V system is limited to 900W.

Yessir.

BFL13 wrote:
You could make it all 48v instead of 24v too if you were starting from scratch.

Yeah, 4 12s in series would be sweet. From much of my reading about batteries, it's better to have them all in series.