Had a chance to go back through recent discussions ...
TreeSeeker - Your breaker panel and power converter is quite clean ... I'd even say remarkably so ... if it weren't for the light switch with an alligator clip attached to it, dangling in mid-air. :E
Based on the age and the label on the power converter, the "with battery charger" circuit is probably a single-stage, non-automatic, old fashion charger ... so, yeah, it'd boil a battery dry and destroy it if you don't keep a close watch over it.
Maya.215 - the gray box in the first picture you posted on July 12th (Federal Pacific with 30, 12, and two 20 amp circuit breakers) is a 120/240VAC breaker panel just like what's in your house. (Unless your house is really old, with a fuse panel instead.)
I'm not sure what the second gray box, in the background, is. It could be a grid/generator cut-over, as require by law and regulation when you have an auxiliary generator.
The large vented grayish black box likely contains the power supply/converter but I'd have to see what inside to be sure. (The fact the top is pop-riveted is a further indication, although it could also mean a previous owner stripped the screw threads and pop-riveted it shut.)
There's one sure sign of an old skool power supply/converter ... they always had a transformer like this:
(It's upside down, but that doesn't matter in terms of recognition ... and operation.)
The picture you posted later is a fuse/distribution panel. The top fuse (labelled BATT+) is the main fuse, which feeds current (left to right) to the metal bus bar on the right. That bus bar, in turn, passes current (right to left) to all the other fuses, to be distributed to all the circuits. (BTW - that fuse panel looks ancient, like something out of the '50s or '60s ... possibly scavenged by a previous owner to replace a faulty fuse panel.)
If that vented box is your power supply/converter, it could have been disconnected by a previous owner or was malfunctioning or simply quit functioning. (Or all three, if it was creating -- real or imagined -- issues for a previous owner.) The fact you consistently read 12.4 volts on your circuits, regardless of what you do, indicates you're running on battery alone.
