Electric Jack Issue/ Battery Storage

OP didn't say he drove anywhere, but assuming his charging circuit is working from his 7 pin while driving, the batteries should have had at least some charge if he did drive.

Fwiw, I've never tried running my jacks from 7 pin, but I have run a tongue jack for a TT with a completely dead battery.

I have jumped my generator from the truck. I originally made a short set, but since I carry 25 ft jumper cables now, I use those.

If it was sitting, then I think OP will need to use his battery cutoff when not using it. The carbon monoxide detectors and LP detectors generally use enough battery power to drain a battery.

Trying to overcome a dead battery, especially multiple dead batteries, can sometimes yield odd results. It drives me nuts watching these "revival" videos on youtube where the host takes one of those wimpy little jump packs, clamps it on to a stone dead battery, and then spending the next 30 minutes scratching their heads as to why the car won't turn over.

Occasionally you can get away with that, but most times you really need to take the dead batteries out of the equation so they're not pulling the entire system down.

It is entirely possible that your truck's charging system was working fine, but it is not designed to jump start a dead battery. The charge line is 10ga at best.

Jumping the battery worked because jumper cables are much heavier and could pass a lot more current.

I parked under a tree for a few days once. With the pv panel blocked, the fridge ran the camper batteries down. I managed to find an extension cord, and attempted to let the convertor recharge the batteries without luck. I eventually found a small circuit breaker that had tripped when the convertor dumped too much current into the pair of dead batteries. The reset was a very tiny button on the side of the device, easy to miss. This open breaker blocked charging from the convertor, truck alternator, and pv panel. I've upsized the cables and breaker since.

Did your truck ever charge the batteries? The wire is unhooked under the hood from the factory and the fuse comes in the glove box.
If you have a quality converter (charger) in the camper just leave the batteries in with it plugged in. If you don't have a good 3 stage converter then vet one instead of toting heavy batteries.

Grit dog wrote:
First part doesn't make sense. Unless you're trying to say the camper batteries were/are dead.
Any smart maintainer will work for battery storage, as will disconnecting them fully charged and not doing anything. Maybe top them up every few months, but not totally necessary either.

The batteries were dead. We left the camper somewhere longer than expected and went to retrieve it only to find no power to the jacks via the truck. A friend jumped the batteries and the jacks started to work. We tried the truck connection when we got home and still no power to the jacks so we used the power cord and got the camper off the truck. I’ll have to check the fuses again.

As for a maintainer, any difference from using the power cord to charge the batteries? Keep them charged? Someone suggested taking the batteries out of the camper and maintain them in our garage.

Finally, what is a popular maintainer to purchase should we go that route.

Thanks a lot everyone.

As Jim said, probably a blown fuse on the truck. I'm not familiar with the Chevy/GMC electrical but there is a fuse on my Ford.

If you take the batteries out a battery tender is your best bet - cheap and won't over charge the batteries. If the batteries were dead they may not recover but a bettery tender might be able to bring them back.

Finally, if it isn't a long power run you can just plug the camper in and let the house power the internal electrics.

mellow wrote:
I would fire up the genny and use the jacks.

You can't start the house generator if battery is dead.

I would fire up the genny and use the jacks.

jimh406 wrote:
If the batteries were dead on the TC, then it's probably the power circuit on the truck. You should be able to look up what fuse it will be on the truck.

I like battery tenders if you take the batteries out. If it is fairly close, I'd just plug in.

Could contribute to dead batteries, but not the sole cause. The truck isn't going to fully charge a pair of deep cycle batteries off the 12V lead unless maybe you drove from here to New York and back without using the camper batteries.
OP, Why not test that pin on the trailer plug first to verify power or not.

First part doesn't make sense. Unless you're trying to say the camper batteries were/are dead.
Any smart maintainer will work for battery storage, as will disconnecting them fully charged and not doing anything. Maybe top them up every few months, but not totally necessary either.