Generator start battery

[jelmore]

I replaced the generator start battery 4 months ago and have used it maybe a dozen or so times with no issues. While waiting for a replacement fan for an inverter, and while plugged in to shore power, I turned off that inverter, one of two, to avoid the noisy fan. The other inverter seemed to keep the house batteries charged. Just in case the house batteries did not stay charged, I kept the generator autostart system on.

After about a week in this state, all the generator lights inside started flashing. The only way to disable that was to unplug the Watchdog module. While checking things, I noticed that the generator start battery charge showed 10V!! Those flashing lights must indicate a low voltage situation.

A paragraph of questions: How did this happen? Could it be that Inverter #1 keeps that battery charged and by having that inverter off the battery drained? What kind of load is on that battery that would cause that much discharge? The Watchdog system? Does that battery even get charged other than by the generator? Could it just be a bad battery?

That battery is a critical link to this entire system. As far as I know, there is no other way to start the generator. I've read about emergency links to other batteries in some installations, but I'm pretty sure my coach doesn't have anything like this.

Perhaps this is something I need to take up with Liberty. Thought I should check here first.

[truk4u]

Jim,

You need Jon to jump in here since it's a Liberty. Harry had the same issue in Branson with respect to the gen battery. You said you shut down the noisy inverter and the other kept the house batteries charged. I think you will find that both inverters are needed for the charging cycle, each charging certain batteries. Your Liberty is setup to charge the gen battery via one of the inverters, so possibly your noisy shut down inverter was the one that should have charged the gen battery.

[jelmore]

If that's the case, one inverter keeps the generator battery charged, it sure makes me wonder what kind of load was on that battery to suck all the juice out of it. It wasn't used at all. And now that both inverters are back on line, the battery isn't charging.

[Jon Wehrenberg]

I can't help on this one. It is possible the battery is bad.

If it turns out the battery tests bad, a new one should show 14 volts on the generator voltage gauge with the inverters on because the generator battery charge is maintained that way. If not there is a problem in the circuit from the house batteries to the genaerator battery, possibly the isolator that should be located in the electrical compartment if it is like my Liberty.

[jelmore]

Talked to Tony in Chicago on this one. In this coach, there is no connection between the generator start battery and the house batteries or the inverters. The Watchdog monitoring system is powered by the house batteries and there are no loads on the start battery other than starting the generator. That battery is only charged when either the engine or the generator is running, not by shore power or the inverters.

Seems I have a failed battery.

[Jon Wehrenberg]

Good to know. That is 100% different from mine. We have been sitting in Spearfish for 4 or 5 days and the generator battery voltage is showing 14+ indicating our battery is having its charge maintained by the inverters. If that was not the case we would be showing around 12.7 volts.

[Kenneth Brewer]

I agree; that is interesting, particularly since we have 2000 Liberty as well. I will check the battery under shore power to see if it is being charged, as Jon suggests. I was the impression somehow that the inverter battery charger, one or the other of the two, if not both, had the generator as one of the loads. I imagine you have a number of POGGers scrambling to confirm their systems now. Thanks.

[jelmore]

All done here. You all go ahead and chat.

With the new isolator in, batteries and inverters on, shore power off, +12V side reads 12.6V and the generator battery side reads 12.3V. Vanner says they expect a .5V drop.

With shore power on and the chargers at the beginning of their cycle, the +12V side reads 14.2V and the other side is 13.9V.

Jon, like you said, all the power sources are connected on a Liberty.

Excellent. Thanks all. (Harry, glad this happened to you!)

[hhoppe]

Jim; When I returned from the POG rally in Spearfish we spent a night in Sparks Marina RV park in Reno. They were having a Bus and Bikers rally there. The big Liberty semi truck and Troy Moody and some other Liberty techs. were there. Upon inspection of my bus they saw I had put a battery switch ahead of my generator battery. I explained I did not want the " Watchdog " system starting my generator while the bus was in indoor storage. They said I could unplug the group of wires below the watchdog control box while in storage. That allows the generator battery to be charged while in storage along with the other house batteries. They had a Solenoid Water Valve on hand to make a replcement I needed and helped with some other items needing repair. I told them we better see that big repair truck and crew at our Oklahoma Rally next October. Us Liberty owners need to keep the pressure on them to do it. Skiff and Jon are you reading this. The Bus n Bikers group had quite a few newer busses. They looked like the high money boys with new toys. Glad you got your problem solved.

[Jon Wehrenberg]

Harry,

While it is nice to have the repair truck, I am of the opinion that teaching the owners how to operate their Liberty would be significantly more important. I feel strongly that most owners do not know the operation of a lot of their systems, and as such often do not even know when something is wrong.

Before anyone can request service, they first have to know they have a problem and a lack of understanding of the coach often prevents that.