Problems with House Batteries

[dale farley]

I just moved my bus after it was idle for 2 weeks. It was not plugged in, but everything was turned off that I could turn off. There was no power available where I had it parked. I have now plugged it in to a 50 Amp service, but my house batteries say "Low", and the beeper by my batteries is beeping continually to warn me of low voltage.

My dash panel shows that the two 2500 watt inverters are charging and shows voltage to be 26-27 volts. I don't know how old the batteries are, but this is the first problem I have noticed. I just turned off the 12V and 24V disconnect switches in my battery bay hoping this will help the batteries charge again.

I am wondering if this low voltage is a sign of one or more bad house batteries? The bus has been plugged in for over 24 hours now. Need some advice. Thanks. Dale

[bill&jody]

you have 2 2500 watt inverters? wow. if you assume your power factor is .8 (a somewhat high assumption), thats 260 amps at 12 volts, if fully loaded.
hubba hubba!

[dalej]

Dale, just cause you think everything is off doesn't mean everything is off. Something is draining your batts. I pulled a battery post off one time and there was a ark, so there is some drain on the batts.

[garyde]

Hi Dale. The first thing to look at is your batteries and their age. Are they Sealed batteries? If not, do they need water? Are any of the batteries boiling while charging? The terminals; have they been cleaned and checked ?
After 24 hours, the charge should be back up to 100 % or close to it unless the batteries are bad. Also, One battery could be no good , causing an inbalance on the inverter/charger.
There are several different instruments to test your batteries, the first would be a digital voltmeter to check the voltage.
If the batteries come up to charge but will not stay there and constantly keep charging, you probably have at least one or more old /bad batteries. Gary

[dale farley]

The manual says when I trip the 12V and 24V switches in my engine compartment that it disconnects everything in the coach except the Electronic Control Unit, but I know there are still several things drawing some current. There are several dash lights that are on even when the 12V and 24V switches are off. I will have to try to check the batteries tomorrow to see if I have one or more bad ones.

[Joe Cannarozzi]

Dale, On ours the inverter will cause an arc like you describe even when it is not on. The fellow who repaired it told us this is normal.

Roadrunner unless you have 2 seperate disconects for the 2 banks of 24 volt batteries the 24's for the bus I dont think get disenguaged when diconnecting the house bank. Thats how ours is wired. Im thinking Prevost installed the disconect for the bus batteries and the converters put the ones on for the house.

[Jon Wehrenberg]

This was discussed somewhere previously, but if you still are drawing current after the master switches are turned off you need to identify those loads. Generally speaking you should be able to kill 100% of all electrical power with those switches and if not it is likely someone other than the converter has gotten creative.

You are finding that one of the problems with adding a load ahead of the master switches is that you can never leave your bus without a source of battery charging power, and I would guess that unless that circuit is protected with a fuse or CB near the batteries, you also have a potential fire hazard.

[dale farley]

Joe, I do have two sets of disconnects. The manual says the ones in the engine compartment disconnect everything, but I am reasonably sure that is only for the bus. The ones in the battery compartment are for the house.

When I turn all four of them off, I still see radio lights, etc. on the dash, so I assume these were added/changed after conversion. One thing that I don't understand is that I can flip all four switches, and when I open my refrigerator, the lights come on, so it is obviously getting power from somewhere. The refer if not running unless I have the dial turned on, but there is still power getting to it from somewhere. I tried flippiing all the breakers in my panel last night, and still did not get the refer lights to go out with the door open. As Jon suggested, I do need to get these things under control.

When everything is turned off, I also see the lights for the inverters and house current status on the two panels on the dash. Is this normal?

[truk4u]

Dale,

The only way to check the batteries is with a load tester and each has to be unhooked and checked one at a time.

With all the 12V & 24V breakers off, you still will have 120V and that's why your fridge light is on.

Try doing a search on batteries, we did tons of this stuff a few months ago.

[dale farley]

Tom,

I'll slap my own head again. I wasn't even thinking about the the 120V being on. I'll check each of the batteries with a load tester and see what I get.