Bad Battery?

llmrealestat · 07-14-2013, 03:00 PM

My house battery keeps going down and the "Dimensions" readout tells me "charger off" and Battery Temp High" Does this mean I have a bad house battery or is there a fix I don't know about? Thanks.

Shadowcatche · 07-14-2013, 07:16 PM

What is the voltage at the battery with no load, and charger off and is the charger actually working, switch charger on and read voltage?

llmrealestat · 07-14-2013, 10:20 PM

Shadowcatche: It fluctuates from between 6.8 and 12.4. When it reached 6.8, it shut everything down for about 2 hours. I couldn't even turn on the generator. I believe the charger is working because it switches from the above message to "float mode" to "charging". It is very hot and humid where we are in Nebraska so I don't know if that has anything to do with it. Our surge guard says we have 120V and 120V (it fluctuates from 116 to 123) and one line has 0 amps and one has 18 amps. We are plugged into 50 amp shore power. We're baffled.

skigramp · 07-14-2013, 11:04 PM

I suggest you read this article on batteries

==> 12Volt Info

In particular there is a table that shows the amount of charge in a 12V battery ... anything below 10.5 is totally discharged ... and 12.6 is fully charged ... so if you are getting this kind of fluctuation there must be something wrong internally with your battery bank ...

My suggestion for a temporary fix would be to disconnect the battery bank and find the single battery that has the most consistent reading near 12.6 and use ONLY that battery until you can get to a dealer.

You can use your MOM switch to start your generator ... you may have to start your engine first ...

llmrealestat · 07-15-2013, 10:45 AM

Thanks Skigramp! That was an excellent article.

BFlinn181 · 07-15-2013, 12:14 PM

I'd suggest you remove and clean all battery terminals and check all ground connections. Dirty contacts could be the cause of the fluctuating readings. Also I'd recommend testing specific gravity in each cell to see if you have any bad cells or batteries. If you turn on 12 v lights in the coach and disconnect shore power, do the lights dim? When you plug in again do they brighten? That will tell you if the converter is supplying power or not. Converter might be connected to the 50 amp leg that is reading 0 amps.
The fact that one leg of the 50 amp service reads 0 amps could be that the plug is bad, the pedestal is bad, or you have a circuit breaker tripped. It also could be that you only have electrical items on that draw from that one leg. A quick test would be to turn on second A/C which should be wired to the other leg. A multimeter to test the hot and neutral wiring in the pedestal would also be a good test. Each hot & neutral should test 120 v, testing across hot to hot should test 240 v. It's not unusual in hot weather when lots are drawing power to have voltage fluctuate, your readings are not out of range.

llmrealestat · 07-15-2013, 12:42 PM

Thanks Bob. We, too, thought the range was okay, but when House Battery display went down to 4 and everything (including the panel) went off, we got really concerned. We will do the tests you suggest. We also have an appt. at a RV repair shop on Wednesday if we can't figure it out.