Need help, not charging house batteries

[Orrin]

Hi, I screwed up and let the house batteries run down to 10.8 volts while I was working on the coach. I had a hard time starting the 7500w Onan generator but was able to jump it off the chassis batteries. Did not charge the hose batteries. Now we are at the camp ground (Northland, just out side Superior, WI) I have 50 amp service connected and still showing just 11.1 volts on the coach batteries.

I am sure that there is a problem with a relay or fuse, but don't where to look or what to look for. The 50 amp breakers seam to be on, front and rear. I hope I have not ruined the batteries.

2002 HR Ambassador with 8.3 Cummins.

Any help would be greatly appreciated. My number is in my profile. Thanks in advance.

 

[TJ&LadyDi]

How old are your house batteries? Because they seem to be taking a little charge (10.8>11.1), it appears the charger circuit is working but the batteries are incapable of taking a full charge. That’s one of the signs of failing batteries.

Specifically, what kind of batteries are they? Standard lead acid, sealed AGM, etc.? And, how many are in your house battery pack? If more than one (likely), you might try disconnecting them individually and testing each battery for voltage. You may find that one has failed and is dragging the other(s) down.

Load-testing is the only really reliable way to test the batteries and most auto parts stores are able to do that, but you’ll have to take the batteries to them. Checking battery voltage with a VOM will only show if one battery has failed completely.

Good luck.

TJ

 

[ww1wxradio]

Is the breaker on your inverter/converter on? Do the interior lights seem to be normal or are they dim??

 

[Orrin]

Thank you both for your replies courteous. I am going to take the coach to Link brothers in Minong wi on Tuesday. We seam to 115 volts at the house outlets. I will let you know how it works out. I have no idea how old the batteries are. There are 4 of them and they are deep cycle lead acid batteries

 

[TJ&LadyDi]

Good plan, Orrin! In general, batteries last 5-7 years with a few failing earlier and a few lasting longer. You may find plastic stickers on the batteries with a month and year of installation punched out. That would provide an indication of their age.

Good luck.

TJ

 

[Orrin]

I think I have a temporary fix. I am going to Walmart and buy a battery charger and bring up the batteries to a full charge. Right now I don’t have enough power to run the fridge on LP.

 

[mbutts4901]

I did the same thing last year with 18 month old deep cycle AGM batteries. After that, they just wouldn't charge. Putting on a charger would show them as fully charged in about 10 minutes, but they would drop back down to less than 11 V thirty minutes after removing the charger.

Hopefully you'll be able to revive yours, but don't be surprised if they no longer have the will to live.

 

[TJ&LadyDi]

I think I have a temporary fix. I am going to Walmart and buy a battery charger and bring up the batteries to a full charge. Right now I don’t have enough power to run the fridge on LP.

If the batteries have failed, buying a new charger won’t fix them! If, by chance the charger does charge them, then you have a problem with the coach’s charging system. I suppose it is a fairly inexpensive test method (and, you can probably use the new charger for other things), but having the batteries load-tested is usually done free of charge at auto parts stores and other battery retailers.

TJ

 

[Orrin]

I charged the house batteries with a regular battery charger. Now reading 13.6 volts. While I was working on it my neighbors stopped to see what I was doing. One is a retired electrician and the other is experienced in rv repair. They had meters and test lights and concluded the everything is working as it should. For now I don’t have a problem . When I get home I will get the batteries load tested and check with my hygrometer. All they could think of was that I had run the batteries so low that the converter would not charge them.

 

[Orrin]

Update: We are still on the road (camping at Hyland RV Court in Ellison Bay, Door County, WI. The converter is still working well. The only thing I have noticed is that when we are driving the alternator charges the chassis batteries, but not the house batteries. There is a switch between them that looks like a big relay that definitely connects to both sets of batteries. I will have to learn how it works and check it out. Anyway, we are good for now and having fun. Oh, BTW this is a great campground, forth time here and we love it.

 

[Joe Hogan]

Commonly referred to as a BIM or BIRD. It is a bidirectional relay that manages the draw of the house batteries on the Alternator. Also manages the draw on the chassis battery when parked.

 

[Joe Hogan]

Here are a couple of images that might help.

First is a battery connection chart posted above the chassis battery.

Next is the main chassis fuse box in the engine bay. Note in the upper left corner you can just make out the Bi-Directional Relay tucked away in the fuse box.