Thor house batteries won't hold charge

[jackpwelch]

I have a new Thor windsport 34p and the coach batteries don't seem to hold a charge even when the switch in Store. They last about 12 hours with nothing on. Am I missing something or could the new coach batteries be bad?
Thanks Jack

[Bob Denman]

Perhaps they just need a really good charging?
It's tough to know how they were treated before you brought them home.
Hook them up, and see if that improves their mood a bit.

Good luck!

[halfprice]

Check the water level also. Mine were very low when i got mine

[Trkyte@msn.com]

The store switch just disconnects the power distribution panel (which houses the converter to charge on shore power).
Do you have a invertor? It is wired directly. Make sure it is off. It draws power even though it's not powering anything.
Another lead that doesn't go thru the store relay is the charge lead to the chassis battery viz either a delay isolation relay or the bird relay. If your chassis battery is good then that not your problem.
Another lead that is wired directly to the batteries is to the hydraulic leveling pump. I can't see that being a problem.
Another lead directly to the batteries is to the generator. If the internal alternator diode is bad it will discharge the batteries.

And of course the radio keep alive lead is wired directly to the batteries. Many people blame this but just like the car in your driveway, it shouldn't discharge the batteries in a week or even a month.

The last trip of mine was on nov eleventh. Yesterday I checked my chassis batteries 12.4 volts. Coach started with no problems, drove it to fill my propane.

Hope this helps.

[jpmihalk]

Chances are the batteries did not receive any maintenance or checks while at the dealer's lot. We had read some "horror" stories about the Harris batteries that Thor had been using and in our research found our unit was almost 1 year old when we made the deal. We had the dealer replace the original batteries and add two more for increased capacity. We also added solar panels to help keep the batteries topped off without using as much generator fuel.

[sky_blue]

Have someone do a specific gravity test on the batteries. This will tell if they have the ability to hold a charge. If not, get 2 new Interstate or Exide Deep Cycle Batteries.

[Laco]

Dealers are notorious for discharging batteries, then charging them, discharging them, charging them, over and over, which is a battery killer for sure. Depending on how long a particular unit sits on the lot, being a demo unit, determines what shape the batteries are in when its finally sold. Have your dealer load test the house batteries, which should shed some light on their condition. If they don't survive the load test, they should be replaced.

[Steamboat]

Now having the same issue as jackpwelch with the house batteries not keeping a charge and the use/store switch not working. I put the switch to “store” and the house lights and the radio remained on, shut the lights off at the switch. The next day the house batteries were down to half charge

[Steamboat]

Continuing... Starting the rig or the generator brought them back to full quickly. To keep them from discharging, I disconnected the ground on both batteries but the house lights and the radio stayed on, that’s not supposed to happen. Thor wasn’t sure why the radio and lights were still getting power. They suggested tripping the 50 amp breaker in the battery compartment to keep the house batteries from discharging. Will have the use/store solenoid checked.

[jackpwelch]

Thanks for the help

[sky_blue]

I have a Vegas. And I know that the radio and front connectors all run off the coach battery, not the house batteries.

If you have an issue, you could install the knife switch the has been mentioned before. Turning that off and putting the Use.Store switch on Store would ensure no battery drainage.

[bevedfelker]

On my 2015 Vegas the radio gets power from BOTH battery sets for two different purposes:

House batteries -- provides power to operate radio and rear view cameras

Chassis battery -- provides power for the station preselects and clock in the radio. It uses the chassis battery because if the house batteries were used for these functions, every time you'd place the USE/STORE in STORE and disconnect the house battery, you'd lose the radio preselects and the clock would reset to zero.

[Trkyte@msn.com]

I have a 17 29h and mine radio is definetly on the coach batteries. I know this because I accidentally blew the fuse and with no help from Thor it took me three days to find it. The keep alive lead is pigtailed off the battery side of the use/store relay via a inline fuse. The switched power lead is fused through the power distribution panel.

[Steamboat]

Seemed to have lost the chassis battery. Disconnected the house batteries to preserve charge since use/store function is not working. Had to use emergency start to get the rig started. Have battery on charger but not holding out much hope that it will take a charge. Have had the ACE since August. Any suggestions for a replacement?

[Bob Denman]

Interstate batteries seem to be a favorite...

[Steamboat]

Thanks Bob. I’m leaning in that direction. Had the motorcraft on charge for several hours and got it to as high as 13 but it wouldn’t go past 70% charged. Not really interested in another Motorcraft but shouldn’t there be some warranty on a battery that I have had for only 5 months?

[99dart]

Originally Posted by Steamboat

Thanks Bob. I’m leaning in that direction. Had the motorcraft on charge for several hours and got it to as high as 13 but it wouldn’t go past 70% charged. Not really interested in another Motorcraft but shouldn’t there be some warranty on a battery that I have had for only 5 months?

If you just bought the MH new, I would guess there is a warranty that would replace the battery. BUT, the battery has probably been in the chassis since Ford built it and that could possibly be a couple years. I would hope that the dealer you purchased the MH from would make it right for you.

[Laco]

I had my batteries load tested at delivery, and then again about six months later. Having heard so many negative comments about the Harris batteries, I was wary of them. They are IMO just OK, but I am not having any particular problems with them. When the time comes, I will replace with a pair of six volt deep cycle, probably Inter State, though I know a battery dealer that sells his own 'no brand', that he has made by Inter State. I have had really good luck with his no brand batteries over the years which cost about a third less than branded Inter State.