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Tigerfan1 · 05-09-2015, 06:19 PM

We have been home from Florida for about six weeks. When we returned home I put the mh in barn and plugged it in to shore power. I have been in the coach several times since we returned and interior lights worked fine. Went out their today and no 12v power. Put a meter on batteries and they are down to 10v even though the coach has been continually plugged in. All plugs work. I tried using an external battery charger but it said battery voltage too low to charge. The four lead acid house batteries are only two years old. I cleaned all battery connections but still won't charge. Checked the circuit breaker on inverter/charger and it is fine. Any way to save the relatively new batteries? How do I determine what caused the inverter/charger to stop charging the batteries? Before we left Florida I put meter on the batteries and the we're getting 13.6 volts when plugged in. The chassis batteries were also down to 12.1 volts but I was able to charge them with an an external charger. I have owned the coach for 10 yrs and have never had a problem like this before. Thanks in advance for any help. Sorry for the long post.

dennis45 · 05-09-2015, 06:27 PM

I assume you checked the water level in the house batteries? I would start by having the batteries load tested because in my opinion, you have at least one bad cell causing the problem.

bonzocfi · 05-09-2015, 06:30 PM

You may have a bad converter.

vsheetz · 05-09-2015, 06:37 PM

If wet cell batteries you can check each cell by dipping one voltmeter lead into the electrolyte. If no change from a cell to the next that's a bad cell. If all ok, try a small amperage charger to bring them up. Once you get them up you can load test them and check specific gravity.

As for the converter charging the batteries, ensure all fuses and breakers are good / not tripped. Got 120vac going into the converter? Got 12vdc out? Got 12vdc out with load disconnected? Etc.

tomwalt · 05-09-2015, 07:11 PM

Disconnect the bank of batteries and test/charge them one at a time - one bad battery could drain/hold down the entire bank.
P.S. Mark the leads you take off so you can get it back together right.

Rotten-Red · 05-09-2015, 08:03 PM

This is probably a stupid question, but you did have your store/use switch in the use position, right? Batteries won't charge in store position.

bluepill · 05-09-2015, 08:15 PM

Quote:

Originally Posted by tomwalt

Disconnect the bank of batteries and test/charge them one at a time - one bad battery could drain/hold down the entire bank.
P.S. Mark the leads you take off so you can get it back together right.

Take a few photos with a digital camera or a cell phone before starting any work. It can really help later.

Trusty source of 12 volt info:

http://www.marxrv.com/12volt/12volt.htm

Rook · 05-09-2015, 08:26 PM

Ditto to post #5........sounds like a shorted cell in one battery.....Rook

"007" · 05-10-2015, 04:39 AM

If you read 13.6 v in FL. with it plugged in now what are you reading?
You can read charging voltage off the battery cut off switch when on which would be your converter charge.
You can read voltage same place with shore line unplugged and will read batteries.
If you can read 13.6, converter OK if not may be failed converter.
May read low voltage off inverter display but you can still charge with stand alone battery charger on your house batteries, had that happen yesterday when we picked up coach to drive and all batteries were dead over winter but eventually started to come back on charger and we jumper the coach batteries to start the coach.
Will take some time to recharge 5.5 low batteries.

Tigerfan1 · 05-10-2015, 08:37 AM

007- when I put a meter on the pos and neg leads going to the battery bank it reads 10v. There is power to the inverter/charger as the green bat temp light is on. I tried to hook up an external charger but it said batts to low to charge. Water level in all batts good. Use/store switch is on. I get no reading on meter over dash that gives you status of inverter and batts. It is off and won't turn on.

"007" · 05-10-2015, 09:40 AM

Tiger, we got the same thing with all the batteries that were dead yesterday no reading of on -off switch display unless you held it on and got a short reading.
Direct reading on ours were 5.5 house and 10 v two chassis batteries.
We kept charging with the converter and had jumpers between chassis and car.
The 8 house batteries are still low even after we drove the coach home but chassis batteries are now up where they belong, have to get power from house tomorrow on this coach a MADP I am holding for someone.
I am going to remove 4 of the house and see if I can get remaining 4 charged tomorrow, will see how that works out.
If you put your battery charger on the house battery lugs even while its reading low charge, what do the battery lugs read while charger is hooked up?
If you can not get any response with the battery cut off or on may have a bad solenoid that will not operate with the low voltage.
The battery ground cables to chassis frame are clean and tight you say.

Tigerfan1 · 05-10-2015, 11:33 AM

007. I cleaned and tightened all terminals in the battery compartment, I will check the chassis ground. Thanks

"007" · 05-10-2015, 05:15 PM

Each battery bank will have its own battery cable for ground to frame maybe separate or together.

Tigerfan1 · 05-10-2015, 05:57 PM

Something weird (and good) just happened, I turned the ignition key on and off and all the 12volt stuff came on. Lights, monitor panel over dash and the batteries are getting a 14.1 bulk charge! Hallelujah !! I am wondering if the battery isolator switch is sticking ? Anyway, what a relief. I still need to trouble shoot what caused this. Thanks for everyone's help especially 007.