Battery Jumping; Plugging into house questions

[MoJo]

Two seemingly basic electrical questions:

1. Say hypothetically the engine battery were to die, could jumper cables be hooked up to the coach battery to jump the engine battery?

and

2. I found an adapter plug that will connect to the cable used to hookup to a campsite's electricity, and will then fit into your regular household 3 prong outlet. Can the van be plugged into a house like this, or is there some sort of electrical incompatability?

[skater]

Two seemingly basic electrical questions:

1. Say hypothetically the engine battery were to die, could jumper cables be hooked up to the coach battery to jump the engine battery?

and

2. I found an adapter plug that will connect to the cable used to hookup to a campsite's electricity, and will then fit into your regular household 3 prong outlet. Can the van be plugged into a house like this, or is there some sort of electrical incompatability?

1. I've wondered the same, but I don't think it's a good idea. The reason is that the deep cycle battery usually isn't designed to supply that kind of amperage for starting a vehicle (some are, depending on how they're designed, for example I think deep cycle batteries intended for boats can be used as a starting battery, as well as the Optima Yellow Tops).

2. Yep, it'll work fine, I use mine a lot. However you should not attempt to draw more than 15 amps through it - in other words, if you're running the air conditioner or microwave, don't run anything else. But fridge, lights, fans, radio, etc. all should be fine.

[ChasingRain]

1. I've done it with some success. I was in a pinch when I had to replace the battery, so it's not a deep cycle (but I haven't had any problems with it over two years...) so your mileage may vary. I've got a solar panel, so the house battery stays charged, but he wiring voodoo means that the engine battery isn't charged by the solar. Since both batteries share a common ground, you only need to hook up the positive terminals. I feel like firing up the generator also provides some extra juice, but in that case, I don't remember you need to 'jump' it, or just let it run for a while to charge the battery.

[skater]

I don't think running the generator will charge the engine battery, for the same reason your solar panel won't.

Although... if the engine is running and the generator is running (or you're plugged into shore power), you probably do have two sources of 12 volt, in which case the engine battery might get a little extra.

[craigmar]

In answer to your question about jumping the two batteries, I have accomplished the jump with no problem and have also transferred the battery positions to start the vehicle, again no problem.

[bryanl]

As for jump starting, it would be preferred to start up the genset first and allow the house battery side of things a few minutes to charge up the engine battery. Connect the jumper after the genset has settled down and is running.

A good battery charger hooked up the genset would be even better (and safer).

Do take appropriate precautions! I believe both batteries share the frame ground so you only need positive to positive. Use care to minimize sparking and other hazards.

As for the connector, I think you are talking about connecting a 30 amp RV plug into a 15 amp socket. These are both 110v and the only likely problem is blowing a circuit breaker on the 15 amp circuit. This means you should watch the load in the 30 amp RV plug side. (of course, don't plug the B-van into itself)

The RV/Marine house battery should not have a problem providing starting current in normal conditions.