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Topic: House Batteries Not holding a charge  (Read 515 times) previous topic - next topic

House Batteries Not holding a charge

1994 Grand Villa U300
2- 4 year old Napa AGM batteries that came with the coach

Our 4 year old Napa AGM batteries that our 94 Grand Villa U300 SE came with, are dying. Cannot get the combined power over 11.56v and now it is dropping down to 10v. Our Xantrex Freedom 248 shows that is outputting 13.5 V on the charging side of things.  I  have taken the terminals off, cleaned every cable, connector and battery terminal.

Our 4 year old Napa AGM batteries that our 94 Grand Villa U300 SE came with, are dying. Cannot get the combined power over 11.56v and now it is dropping down to 10v. Our Xantrex Freedom 248 shows that is outputting 13.5 V on the charging side of things.  I  have taken the terminals off, cleaned every cable, connector and battery terminal.

Let me add to this. All of this started three weeks ago. One day the voltage just started dropping. I started testing things, one of my batteries was at 4.96v and the other is at 12v but none of my 12v system worked at all. I understand why, but here is where is gets weird. Jana and I were laying in bed and boom all the sudden the lights in the kitchen and bedroom came on ( we left some switches on I guess) and the amp-hour meter reads 13.4 volts. This was exactly 7 days from the day the issue started. It held for 4-5 days I couldn't find anything wrong, then the voltage started dropping, can't find anything wrong with the system then 7 days later, everything works fine



I am at a loss. Any ideas?

Re: House Batteries Not holding a charge

Reply #1 –
My guess is that the batteries weren't properly maintained and/or were discharged down too low too many times and are now kaput.

Re: House Batteries Not holding a charge

Reply #2 –
Quote from: BrettandJana –
1994 Grand Villa U300
2- 4 year old Napa AGM batteries that came with the coach

Our 4 year old Napa AGM batteries that our 94 Grand Villa U300 SE came with, are dying. Cannot get the combined power over 11.56v and now it is dropping down to 10v. Our Xantrex Freedom 248 shows that is outputting 13.5 V on the charging side of things.  I  have taken the terminals off, cleaned every cable, connector and battery terminal.

I am at a loss. Any ideas?


Try a cheap battery charger (not a smart charger).  If you can get them to 12 plus then maybe the inverter charger wil be able to take over.

(Or) perhaps one of the batteries has one or more  dead cell(s). Might need to try charging one at a time or get them independently load tested.

Re: House Batteries Not holding a charge

Reply #3 –
Quote from: Elliott –
My guess is that the batteries weren't properly maintained and/or were discharged down too low too many times and are now kaput.

We purchased the coach in April and while the previous owners were sticklers for maintenance ( he was a pilot in the Navy) and had immaculate records in his log books for the coach, and MOT had done much of the service, I don't know how the batteries were treated while in they were driving between campgrounds.

Re: House Batteries Not holding a charge

Reply #4 –
It may be that one battery has a dead cell. That would drag down both of them. You should get more than 4 years out of them but at this point my guess is they are both toast. 

Re: House Batteries Not holding a charge

Reply #5 –
Separate batteries and see if one is bad. Just run with one battery for a while then swap. Like Slim said, one of the 12 cells in both batteries could be bad.

Some buy start batteries with long warranties (like Costco) to use as House batteries.
 

Re: House Batteries Not holding a charge

Reply #6 –
Quote from: BrettandJana –
1994 Grand Villa U300
2- 4 year old Napa AGM batteries that came with the coach

Our 4 year old Napa AGM batteries that our 94 Grand Villa U300 SE came with, are dying. Cannot get the combined power over 11.56v and now it is dropping down to 10v. Our Xantrex Freedom 248 shows that is outputting 13.5 V on the charging side of things.  I  have taken the terminals off, cleaned every cable, connector and battery terminal. 

Let me add to this. All of this started three weeks ago. One day the voltage just started dropping. I started testing things, one of my batteries was at 4.96v and the other is at 12v but none of my 12v system worked at all.

I am at a loss. Any ideas?

The battery that won't hold voltage is internally shorted.  The active plate material flakes off and drops to the bottom of the battery case in use, and when the pile reaches the bottom of the plates, shorts them together.  Sorry for your loss.  We experienced the same sort of failure earlier this year.

Your Xantrex Freedom 248 is showing an output of 13.5V, most likely because it is rolling back the charging voltage to keep from trying to provide more current than that which it is able to provide.

In our case, the power supply had rolled the voltage back to the elevenses and was pouring 60A of current through the battery, as evidenced by a case temperature of 175°F,