Can a bad house battery cause a generator to stall?

[nadsab]

Hi,

Just wondered about this. Generator is slow starting, seems to run fine for a half hour, then stalls out...

Is the first thing to do in troubleshooting, buy a new battery?

After running or being plugged into 110 for a long time, battery can not hold a charge...

[tatest]

FW5000 of that vintage, your generator shutting down is a likely different problem from whatever battery problem you might have. The only connections from house battery to generator are a heavy cable to provide starting current and a lighter wiring to the remote switch and hours meter, if you have that. If you can start the generator, those connections would appear to be good.

The generator will shut down for low oil supply, or if it detects a problem with the 120V circuits that could damage the generator (e.g. a short circuit). I don't know whether the generator checks itself for overheating; if it does, that could occur after running for a while.

[DrewE]

When the generator is running, the converter should be supplying 12V power to it (and the battery). I don't know if the generator requires 12V power while running for the control circuitry; probably depends on the generator model. It stands to reason that some, at least, might.

Do check that your battery is indeed charging whilst on shore or generator power--that is, that the converter and wiring between it and the battery are working properly. No battery charger will lead to the battery being run low if you aren't careful, and that will lead to battery damage if the battery gets discharged too deeply too frequently. (Also verify that it isn't putting out too high of a voltage and cooking the battery....)

If the generator is slow cranking when the battery is fine and fully charged, it could be an electrical or ground connection to the generator, a faulty starter on the generator, etc.

[Dragonfly]

PS: That was good advice to check the water first before replacing the batteries. Also check the terminals to be sure they are clean. Perhaps wash them with baking soda and water. Finally, if you know how, use a meter to see if they are actually receiving a charge.

Also, after you charge them up (assuming they take a full charge) measure their output, even if all you have is a cheap 12volt plug in meter. If the output is good, shut off the battery disconnect so there is no power consumption (except the CO2 detectors etc which are on all the time). If the battery holds power when you are shut off for a day or two but loses power when the battery disconnect is on, then something is using power. Don't forget to check lights hidden in the outside storage compartments. If it isn't something obvious like that then you will have to go hunting for what is sucking down the power.

Finally, if you don't have some sort of unknown power drain and it is just a bad battery, especially if you have had to replace them after only a year or two, remember that even though deep cycle batteries are meant to be run down then recharged over and over, running them too low, too often will significantly shorten their life. Running them dead is even worse for their longevity.

[Dragonfly]

In some set ups a house battery acts like a "filter" for power. When my house batteries not just went bad but were disabled (they cracked open), I had no 12 volt nor 110 either when plugged in or, on generator. With a new battery power was restored.

If your generator starts using the house battery, a bad one may cause the generator to turn over more slowly. (Although with the truck engine running you should have full cranking power). However, I can't think of a reason why a bad battery would cause the generator to eventually stall out unless maybe there was a heavy load e.g. via a short or something like that.

Note that when exercising your generator once a month or so which is important to do, you should do so with some load on it e.g. the air conditioner. I don't know if running the generator with no load would cause it to quit after a while.

It sounds like you need a new battery anyway (be sure to check the battery water first) so get it and the generator should crank more strongly. If the generator still stalls out when running, with some load on it, then you might have a different problem.

[nadsab]

I will check the water level now.

Reason why I asked this, last time we replaced the battery, it was marginal but when we took it in, the people at nationwide battery said one of the cells had a short in it - a short in the old battery that is, not this one. So I was thinking something like a short within the batt would cause it.

[chuckbear]

Before you buy a new battery you might want to check the one you have, find out why it's not charging if that is the case and determine if it is in fact bad or something else is going on. Unless the battery is completely dead, and receiving nothing from the charging source, your generator should not shut down because of this. Is it not holding a charge, or is it not charging. If it's charging and then loses the charge after shut down, then yes, start with a new battery. Have you checked the water level? Chuck