Dual battery set-up using chassis battery
Has anyone incorporated their truck's OEM 12v battery with their camper's battery(ies)? I'm brainstorming a way to do this and would appreciate some input. I'm thinking that if I run large (1/0g) ...
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I have a Xantrex 2000-watt pure wine wave inverter.
The first thing you need to know about using one is you have to put IN what you get out, plus a bit since things aren't 100% efficient.
2000 watts at 120 volts (the theoretical inverter output) requires about 170 amps input at 12 volts!
The battery specs are one thing, but how much current you get at the other end of the cables is another thing.
Also, a 100 amp-hour deep-cycle battery isn't necessarily good at producing 100-amp sustained output. They're better at producing 1 amp for 100 hours... although in reality you only get about half that because when they're halfway drained they don't make full voltage anymore - plus it's bad for them. So, you need a bank of them, at least two but four is where they start to work well.
You'll need very heavy, VERY SHORT cables.
1/0 gauge long enough to reach your truck battery won't be enough, you really need the inverter to be located right next to the batteries.
I've used 2-gauge, but piled on three sets at once, only two feet long, and it's hard to get much over 1000 watts through them.
The other thing is all that power has to come from your alternator. You'll need somewhere around 100 amps while your A/C is running. That's a lot.
There's usually no such thing as running an A/C for short periods of time. It's gotta be on and stay on if it's gonna actually cool your camper.
I think it's foolish to use your starting battery for any other purpose.
Bottom line, it's really not practical to run an A/C this way. A/C is generator territory.
The first thing you need to know about using one is you have to put IN what you get out, plus a bit since things aren't 100% efficient.
2000 watts at 120 volts (the theoretical inverter output) requires about 170 amps input at 12 volts!
The battery specs are one thing, but how much current you get at the other end of the cables is another thing.
Also, a 100 amp-hour deep-cycle battery isn't necessarily good at producing 100-amp sustained output. They're better at producing 1 amp for 100 hours... although in reality you only get about half that because when they're halfway drained they don't make full voltage anymore - plus it's bad for them. So, you need a bank of them, at least two but four is where they start to work well.
You'll need very heavy, VERY SHORT cables.
1/0 gauge long enough to reach your truck battery won't be enough, you really need the inverter to be located right next to the batteries.
I've used 2-gauge, but piled on three sets at once, only two feet long, and it's hard to get much over 1000 watts through them.
The other thing is all that power has to come from your alternator. You'll need somewhere around 100 amps while your A/C is running. That's a lot.
There's usually no such thing as running an A/C for short periods of time. It's gotta be on and stay on if it's gonna actually cool your camper.
I think it's foolish to use your starting battery for any other purpose.
Bottom line, it's really not practical to run an A/C this way. A/C is generator territory.
