Question for electricity people

[Spider]

Here's a hypothetical:

I've been looking into battery banks for storing some power from a couple solar panels (or even for my pickup, so I've got all the power I could use when out in the sticks,, but I'd charge that off the alternator) or whatever, and am wondering if there is some way, perhaps using relays, to wire 10 12 volt batteries in parallel for 12-15 volt DC charging, but then have them run in series at 120 volts AC for running household loads though an inverter...without having to go through and rewire them, and probably zap the shit outa myself repeatedly in the process.

Reason I ask is because stepping 12 volt up to 120 with an inverter results in about 10 times as much amperage draw to do the same job. I could run waaay more efficiently at 120, get a lot more amp hours out of the bank. 10 times as much, really.

Or is this just asking for a way to blow up a bunch of batteries?

[Professor]

You could build a large "circuit board" that all the batteries are connected to. The wiring on the board would be copper rods, not wires, though. In one mode, the rods would be arranged in parallel. Then, with the pull of a lever, all the rods would rotate on an axis and connect in series. Think of a RR switch, and you get the idea.

[Aaron]

[Spider]

[Mo~]

Two things I don't do. Anything beyond basic electricity and basic plumbing. I will gladly pay someone +$75/hr so I don't get shocked and so I don't touch poop. That's just the way I roll.

[Professor]

[Professor]

What about a power inverter? Instead of changing the batteries and their wires around, what about just changing the power as it exits? I have a few of those things hanging around the house and use them often when I want to run a household item out of my car (like a TV) or jumpstart my car by plugging it into a wall socket.

BTW, 120vAC doesn't hurth when you get shocked. It just makes your arm tingle a bit, like hitting your elbow. 12vDC will knock you down. Coincidentally, it also will weld - I once accidentally welded a screwdriver to the fender when I touched the positive terminal and the fender at the same time. Had to cut it off with a hacksaw.

[Spider]

Well, I'd need an inverter regardless to get to AC for household stuff. What I'm trying to avoid is stepping up from 12 volt to 120 volt, which is what I'd have to do with the batteries in parallel. You use 10 times as many amp-hours going from 12 to 120 volt, so 10 times less running time. With the batteries in series I get 120 volts DC, and only need to switch it to AC, which is easy enough, and don't have any loss from stepping up the voltage.

Trouble is that I can't charge the batteries from a 12 volt solar panel if they are pushing 120 volts. I'd have to have a whole bunch of solar panels wired in series as well, to get their voltage up to 240 or something, so that I could charge a 120 battery bank. Soo, need some way to switch them without having to physically rewire them. After googling to hell and back, honestly, designing a "circuit board" as you suggest sounds like the way to go.

Not really any consumer items I can find that do this, as pretty much everyone just runs off of 12 or 24 volt, and leaves their batteries in parallel. They just eat that 90% loss from the difference in voltage.

I'm basically trying to avoid that, but am a novice with electricity.

As to the 12 volt welding, ya I've been there too lol. Pretty sure thats more to do with the crazy 600+ amps of power the battery can supply, as opposed to the mere 20 amps in your wall socket.

Which leads me to worry about sticking a bunch of 12 volt deep cycles in series. If they can supply 600 amps each, then thats 6000potential amps going across that last battery. Even at only 120 volts, 6000 amps is enough to vaporize shit. Thats a quarter million watts. Not that I'd ever draw that much, but if something were to short out somehow....eek.

Maybe this is a bad idea. Maybe thats why there is no out the box solution. Because its crazy.