Generator Won’t Start

[Kevarino]

I have a 2007 Winnebago Tour with an Onan 8000 generator. I let the house batteries go too low and can’t start the generator. Does it use house batteries to start?

I have the Motor running to see if that will charge them enough.

[ksg5000]

Kevarino wrote:
Thanks everyone. And thanks for the aux battery button idea, I thought that was for starting the main engine with the house batteries.

Just after I posted, a friend came by and we ran a jumper from the positive side of the house batteries to the positive side of the chassis batteries and that did the trick.

In most rigs turning on the engine switch does the same thing (connects the two sets of batteries). You should consider testing whether your battery isolator is working properly.

[Kevarino]

I think they were toast when I bought the rig, that is why I’m having all these issues. I’m planning on replacing them as soon as I can.

[CA_Traveler]

Have the batteries load tested to see if they are still OK. Badly discharged batteries can have a very short life.

Keep the batteries fully charged or add full disconnect switches to the batteries.

[Kevarino]

Thanks everyone. And thanks for the aux battery button idea, I thought that was for starting the main engine with the house batteries.

Just after I posted, a friend came by and we ran a jumper from the positive side of the house batteries to the positive side of the chassis batteries and that did the trick.

[SAR_Tracker]

while I don't have 2 different sets of batteries, I've had my toyhauler batteries go dead after running the furnace all night. I have a small, 2-stroke generator (~800 watts) that I carry for just such an emergency.

[gbopp]

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[gbopp]

Make sure your battery terminals are clean and tight. A little corrosion can cause problems.

[ksg5000]

Generator usually need a fully charged battery to startup - many will turn on the engine to combine chassis/coach batteries to insure that max capacity is achieved. Charge your batteries b4 trying to start otherwise starting just further depletes batteries. Also - make sure all battery/ground connections are clean - including those attached to generator.

[smarty]

i carry a small jumper box for this very reason. We boondock alot and had this exact same issue few years ago. Jumper box is the way to go

[CA_Traveler]

In my case both banks are charged from solar, shore and gen. Not sure why Monaco used the house battery for the gen. I'm doubtful that the chassis batteries are any better for gen starting than the house batteries given the much lower amps need for the gen vs the engine. Battery bank size might also be a factor.

Perhaps trying to keep the chassis battery charged and avoiding the potential of a running down the chassis battery due to gen start issues. It can take a lot of juice to start the engine especially in cold weather and certainly engine starting is more critical than gen starting.

[DrewE]

camperdave wrote:
yeah, starts off the house batteries. I had dead house batteries once (dumb mistake...) I started the engine, then waited 20 or so minutes until the house batts had enough juice in them to fire up the genny.

Stupid to have the generator start off the house batts, as when I need the generator is when those batteries are in need of a charge! Seems like it should be fired off from the chassis battery (which is a better starter battery anyway than the deep cycles).

The generator needs 12V power when it's running, not just to start it. If it were connected to the chassis battery and there were no provision for charging the chassis battery from the house battery (as is not at all infrequently the case), you'd run the chassis battery down using the generator for a somewhat extended length of time.

There are tradeoffs to every setup. Some might suggest that having a separate generator starter battery, dedicated just to it, with some means of charging it when the generator is running is the best option of all; but of course that adds complexity and is yet another battery to maintain.

[camperdave]

yeah, starts off the house batteries. I had dead house batteries once (dumb mistake...) I started the engine, then waited 20 or so minutes until the house batts had enough juice in them to fire up the genny.

Stupid to have the generator start off the house batts, as when I need the generator is when those batteries are in need of a charge! Seems like it should be fired off from the chassis battery (which is a better starter battery anyway than the deep cycles).

[azdryheat]

You can push your aux battery (emergency) button on the dash to use the chassis battery to start the genny.