Community Forums

SewFishy · 09-01-2022, 05:23 PM

So.

We rode back up from Gulfport and parked our rig for few weeks in storage.

Our engine start batteries wouldn't crank the rig so we cleaned contacts, No go. Replaced engine start batteries. Fired right up. However.

The Onan 8K generator will not crank. Nothing. Our house batteries 4X6 V are also sitting at 3.4 and looking like the fat lady has sung (the famous bulging).

Our question is: "Does the generator preheat/starter motor receive its 12 V from the house batteries (via the inverter) or from the start batteries?

Panel on generator has nothing lit. Circuit breakers are in.

If should start from the start batteries anyone have any further suggestions?

We plan to replace the house batteries as soon as $ allows.

Thank you

twinboat · 09-01-2022, 06:38 PM

The generator starts from the house batteries.

The inverter has nothing to do with starting the generator, it makes 120 volts when none is available.

onebrit · 09-02-2022, 05:46 PM

Hi
Do you have a jump pack or another vehicle you can jump from to see if you can get the engine to crank? You will need a fully charged system to try and run the generator.
Good luck
Onebrit

Duner · 09-02-2022, 10:56 PM

If you run the engine for 20 minutes or drive an hour or two the house batteries should come up to 13 volts and start the generator. But since the batteries are shot, the voltage will drop back to 3-4 volts again.

FIRE UP · 09-04-2022, 12:25 AM

Quote:

Originally Posted by Duner

If you run the engine for 20 minutes or drive an hour or two the house batteries should come up to 13 volts and start the generator. But since the batteries are shot, the voltage will drop back to 3-4 volts again.

Hey Bill,
The OP states his house batteries are "bulging". That's not good. I've had that situation a time or two and each time, my house batts where shot. If there's damaged cells, you could drive across Arizona, and it wouldn't help the charge status of them. If he's got the 3.4V (assuming that's what the "3.4" means) volts, it's also highly possible their completely shot already. House batteries, or even engine batteries don't like to go down that low.

But it may be possible to bring them back to life by some engine running or driving. Stranger things have happened.

QD gens have a delay in starting if, IF, there's some cold temps involved. The delay is the glow plugs warming up to a given amount/temp before the little Kubota's ECM will allow for engine cranking. With the temps the way they are all over the U.S. in the last couple of months, I doubt the OP is having any temp delay starting issues. The battery connections for the QD gen live in an ugly environment right at the bottom and backside of that little Kubota.

It's possible they could have corroded and or loosened up on one or the other. They're not all that hard to access and check conditions.
Scott

jerichorick · 09-06-2022, 05:30 PM

Quote:

Originally Posted by SewFishy

So.

We rode back up from Gulfport and parked our rig for few weeks in storage.

Our engine start batteries wouldn't crank the rig so we cleaned contacts, No go. Replaced engine start batteries. Fired right up. However.

The Onan 8K generator will not crank. Nothing. Our house batteries 4X6 V are also sitting at 3.4 and looking like the fat lady has sung (the famous bulging).

Our question is: "Does the generator preheat/starter motor receive its 12 V from the house batteries (via the inverter) or from the start batteries?

Panel on generator has nothing lit. Circuit breakers are in.

If should start from the start batteries anyone have any further suggestions?

We plan to replace the house batteries as soon as $ allows.

Thank you

If the batteries are swelling get them out of your rig ASAP. They could split. I have not heard of AGM fires but anything is possible.
I have had great help from these folks: https://www.bargainshore.com/
I bought 6-12V G35 AGM batteries from them a few years ago. Working just fine and the price was better than most.