So yesterday I hooked up my Battery Minder to the second set of batteries, which basically meant I was using one set of batteries to charge another. What could possibly go wrong? It didn’t even occur to me until after sundown that this might not be my finest idea ever. The Minder has four charge settings: 2, 4 and 8 amps. I had it set for 4. A 4-amp after-dark draw on my little 4-battery bank is not the apocalypse, but it is noticeable. I wouldn’t want to leave it on all night. So around 8 PM I went out and unplugged it. Didn’t matter; the batteries were pretty much full anyway.
So this morning I figured I should finish hooking things up. I switched off the inverter and the circuit breakers to the solar panels, then used up the last of that heavy-gauge wire Big Brother sent me to run a line from the #2 charge controller to the … well, I guess I may as well call it the #2 battery bank. Up to today the only thing they were connected to was the powershed lighting, but now I disconnected the whole 12v circuit from the #1 battery bank and switched it to #2. Everything fine, no unexpected arky-sparky, I turned everything back on and everything works great. Just as
This is a minor problem but I’m very annoyed that it never occurred to me for a moment until I saw it happen: Now I have two separate battery banks, and of course my indoor voltage readout can only be connected to one of them. The one that runs my 12v lighting. Which is absolutely not the one whose voltage concerns me most of the time, because a 12v LED draws hardly anything while all the real draw is coming from the AC system.
I could fix it, but it would mean trenching yet another line between the cabin and the powershed. A much simpler solution would be to switch the cabin 12v lights back to the #1 battery bank. Which really eliminates any practical reason to have the #2 bank at all, but probably this is going to annoy me badly enough to actually do that. Bother.