Since hooking up the new inverter, new batteries, and getting the fridge going ... something still isn't quite right. I think the calibration of the inverter is off, and probably the wiring solution I went with isn't stellar either.
When the fridge is running normally it pulls about 8-10 amps. It's really the highest load we have in the cabin. The only other power consumers are a laptop and a 40 watt light bulb.
But when the fridge kicks on, it suddenly starts trying to pull about 32 amps. The lights flicker and we lose the rest of the power for a few seconds and then everything comes back on. The fridge is running normally from there.
My battery system is 24 volts. I have it set to cut off at about 50% battery power, but when there is no incoming power from solar (such as at night) then the voltage drop from the fridge kicking on will drop the voltage so low that the inverter shuts down, thinking the batteries are at 50%. I go outside then to see why we don't have power and I find that the batteries (which have no load on them) are at about 75%.
Very frustrating. As a trial run for the rest of the week I recalibrated the cutoff point so that we don't shut down at 50% and then first thing in the morning I'll check the batteries to see what percentage they are at. If they are above 50% then I'll probably remove the cutoff altogether. If they fall below consistently then I've got to find another solution.
The wiring solution isn't ideal. It's a power strip and a bunch of extension cords. They aren't even very good extension cords and I bet they can't really handle 32 amps. That might be part of the problem right there. The inverter could probably handle a second or two of 32 amps, but it can't handle the 5-6 seconds of it since I'm trying to suck up Lake Eerie through a soda straw. I guess it would not be too terribly difficult to run some 10 gauge wire from the inverter to the cabin and then to hook up some sort of junction box or even just a regular plug. We really only need a few things in the way of electricity in the cabin. One power strip has served all of our needs so far.
Ah well. There will be time to figure this out. There was a time when I couldn't look at a tomato plant and tell that it needed water, so I guess there will come a time when I understand how solar power (and electricity in general) works and can just sort this stuff out properly.