Starting Generator with dead batteries

[RamblinAnne]

So I bought a TC that I'm currently remodeling. The generator seems to be in good condition (Onan 2500, propane). When I first got it, I tested it and it ran fine. But the battery that came with the camper (12V Group 31 AGM) is totally dead. Now, I can't get the generator to start. (I still find it ridiculous that I need charged batteries to start my generator to charge my batteries).

Anyway.. I will get new batteries eventually but I really just want to run my generator here and there to keep her in good shape. How am I supposed to start it up without working batteries?? Can I use my truck to jump start? I plug into my house's 110V once in awhile for power while I'm working in there but I guess this doesn't do anything to help it start up? Should it? Is something wrong?

Sorry so many questions.. I am clearly a newb.

[ticki2]

Or a loose/dirty battery connection . Have you checked the voltage directly at the battery ?

[kohldad]

Sounds like you have a battery disconnect switch some place. Even a dead battery should run an LED light for a couple of minutes just from the surface charge.

[RamblinAnne]

KD4UPL wrote:
Plugging the TC into your home's 120v should keep the battery charge. If that's not working you need to figure that out too while you're working on the camper. Having it plugged in for a few hours should charge the battery enough to start the gen.
Otherwise, jumper cables.

Hmm.. I wonder if there's an underlying issue other than the batteries just being completely dead? A friend of mine told me that once an AGM battery is dead, there is no reviving it. The one I have won't even hold a minimal charge. The only time I have power is when I'm connected to 120V. As soon as I disconnect, I have no power at all, I can't even turn on an LED light.

Like I said, not worried about the battery. It's garbage and I want to upgrade to a bigger bank anyway. Just hate to let the genny sit without running it here and there. No worries about cables reaching. The TC is off the truck so I can pull right up.

[KD4UPL]

Plugging the TC into your home's 120v should keep the battery charge. If that's not working you need to figure that out too while you're working on the camper. Having it plugged in for a few hours should charge the battery enough to start the gen.
Otherwise, jumper cables.

[jimh406]

I built a small set of cables to reach from the cab to the battery compartment with 12 gauge ancor duplex wire and some alligator clips. It worked fine to jump the generator. It's also tiny so I leave it in my truck. It's important to make them as short as possible with this small wire.

Of course, really long jumper cables would be better. I have those to, now.

[pianotuna]

RamblinAnne,

Jumping a dead battery may be hazardous. Please use precautions.

[RamblinAnne]

Thank you guys!! I figured this was a relatively simple solution but I wanted to make sure before I did something potentially dangerous.

[Kayteg1]

My camper is having 30 amp charging cable from the truck, so when my camper battery would not turn the generator, starting the truck engine, giving it 1 minute to restore camper battery was enough to turn the generator.
For generator starting you can get one of those cigarette pack-sized battery and keep it separately.
I hope you have good converter. Mine from 2004 has some tricky power management, that with high current will overheat and shut down for several minutes.
Basically useless for quick charge, that is why I carry computerized 25 amp charger.

[Reddog1]

I can't help you other than suggesting jumper cables long enough to go from the truck batteries to the generator.

Your question reminded me of what comes first, the chicken or the egg.

Wayne

[enblethen]

Yes, jumper to the TC battery and start it up. Disconnect jumper cables. Once started, it should charge the battery via the converter.