house batteries not charging completely from vehicle battery

[RTLover]

Hi,

We have 2 fairly new house batteries for our class B. It seems that we can drive for approx 2 days and then the batteries are dead. We have owned this vehicle for about 3 years and can't figure out the problem. We have had people check the alternator and said that was good as well as the vehicle battery. Every couple of days we have to stop at campground and plug into electricity and use our battery charger to recharge house batteries. Then we are good for another 2 days. Could there be some fuses our reset buttons that need some attention. It also seems that the wall plate that shows battery condition can say fully charged. If I try to run the inverter to run a small crockpot while traveling, the battery will be down to the first light in a very short time. Any help would be greatly appreciated.

[g1g]

I would check the voltage of all the batteries with a good meter and also under a load then start the vehicle and recheck the charging voltage. The charging voltage should be more than just the batteries or it is not charging. Then turn off the vehicle and take off a battery cable from the house battery and see if there is some type of short. There shouldn't be much of a current draw, if there is that could be your problem. I would also leave the cable off for 2-3 days and then check them. If they go down then the batteries are no good.
That is about how I would go about it.

[markopolo]

That's good advice.

My 2004 Roadtrek had a circuit breaker on the cable from the isolator to the house batteries. If you check the house battery voltage like G1G suggests and you don't get 14+ volts at the house batteries with the motor running then that breaker could be open or faulty.

It was the automatic reset type and I think it was 30 amp. '98 Roadtreks had a 40 amp breaker on that line. I think you have a Leisure Travel van but it probably has something similar.

[VernM]

A slow cooker powered from an Inverter and batteries is going to draw an awful lot more current than you suspect. Roughly 10 times that of a 120 volt one on 120 volts.

[Mike]

Originally Posted by markopolo

That's good advice.

My 2004 Roadtrek had a circuit breaker on the cable from the isolator to the house batteries. If you check the house battery voltage like G1G suggests and you don't get 14+ volts at the house batteries with the motor running then that breaker could be open or faulty.

It was the automatic reset type and I think it was 30 amp. '98 Roadtreks had a 40 amp breaker on that line. I think you have a Leisure Travel van but it probably has something similar.

I think the breaker between my isolator and the 2 coach batteries is a 50 amp now. If it ever stops raining
and warms up again I'll look. It's right next to the isolator on the frame under the passenger side of the
engine compartment, IIRC. I wonder if there are any other 12V draws that are on besides the slow cooker?
CO/Propane detector maybe? Any hidden courtesy lights on that aren't obvious because of their location or
just aren't obvious in daylight? Any other vampire accessories that might draw on the 12V coach batteries?
Even a clock radio or other insignificant draw could contribute to a dead 12V coach system.
I would agree that a battery meter on either coach positive batt terminal with the engine running should show
over 14V DC. If not something is wrong either alternator to isolator (not likely), or isolator to batteries(possible),
or one or both batteries are failing (best guess), or my old nemesis, corroded battery cables at the battery posts
interfering with charging. I think the battery level indicator will show fully charged even on an almost dead battery
when it's just been recharged, astheir total capacity to hold a charge diminishes over time. The batts could be down
to 10% max capacity, but when freshly charged, will probably still show 100% on the monitor panel. Normal, I think?
What type of batteries are they? Wet cell, gel cell, AGM? If they're wet cells have a look at them for water/electrolyte
level.

[TinyoneRV]

I have a similar problem with my 04C190P RT. It seems I get a fairly good charge from the shore power or generator but will discharge to almost nothing when driving. This seems to be a new problem that developed last week during our short run to the Outer Banks. If you solve your problem, please post your solution. As soon as we get some sunshine I'll check the battery charge voltage and the breakers.

A related question: when running the frig on 12 volts are you on the coach batteries or the engine battery?

Thanks.

[markopolo]

Originally Posted by TinyoneRV

..............A related question: when running the frig on 12 volts are you on the coach batteries or the engine battery? .....................

Fridge on 12v is running on the coach batteries.
However, if the van motor is running then the alternator is charging both the coach batteries and the engine battery. So when you are driving with the fridge on, the coach battery won't run down.

[Mike]

Originally Posted by markopolo

Fridge on 12v is running on the coach batteries.
However, if the van motor is running then the alternator is charging both the coach batteries and the engine battery. So when you are driving with the fridge on, the coach battery won't run down.

I would add, from personal experience, my batteries start draining rapidly when the fridge is on 12VDC,
almost the second I turn the engine off. I've checked the monitor panel (sorry, it's all I've got) and expected
green for charge level, but it's already dropped to orange/yellow. If I then turn the fridge off, it shows green
again, which I also find puzzling, but happily accept.

[TinyoneRV]

I wonder if this has something to do with the battery switch. I've seen conflicting advice regarding whether this switch has to be on or off to supply charging current to the batteries when driving. I ususally drive with the frig on 12V. If I'm not getting current from the alternator, this would deplete the batteries pretty quick.

[Ron J. Moore]

I read this and re-read and wonder if you have the tv plugged in and the toggle switch on the invertor in the inccorect position?
When we got our '04 190P the tv was plugged in - and not knowing any better, I left it plugged in and the battery was draining. Someone put me onto the toggle on the invertor and when I read the manual and made the switch, along with unplugging the tv, my problem was solved.

[TinyoneRV]

Ron,
Yes, I've done this accidently a couple of times. Even though the TV is off, the 12 volt to 110 volt to 12 volt conversion draws some power and I think that was part of the problem. Nonetheless, even when watching the power carefully and with all the "stuff" off I still don't seem to get a full charge.

[Mike]

I was under the impression that for the fridge to be running on 12V, the coach batteries
have to be enabled. So, we normally drive with them enabled anyway to run the fridge (but
turn them off when we refuel) and so we can use the map lights after dark, and the other cabin
lights when we need them. We also leave the water pump on sometimes after it's primed,
it seems to stay primed longer that way, and we find it doesn't go through the groaning of
re-priming as often when we next use the water. I don't think it draws much when left on
either. So far running like this hasn't caused us any problems we've noticed.

[Jon_K]

I had the same problem. The battery separator was the problem. It seemed to be related to heat. It tested fine when cold. I bought a replacement online and installed it myself. That cured the problem. That's on a 2008 RoadtTrek 190. Take precautions to avoid shorting the battery when doing this.

[Davydd]

There are so many reasons. To reply intelligently to this we need more info. You can destroy fairly new batteries with poor battery management.

[RTLover]

We took our Leisure Traavel to our local mechanic. Had him look at 3 50A circuit resets. Found out they are automatic, so that wasn't the problem. About a year ago we had an RV repairman look at the isolator and said it wasn't working. I'm not sure what its called, but he replaced it with something that is round. Anyway our local mechanic checked batteries and got to really looking and found this replacement was grounded in two places. It wasn't transferring a charge from car battery to house batteries. He then changed it over and put a fuse there and hooked a wire to a live wire for windshield wipers. Works now. Its maybe not the correct way to do it, but if it works, what the heck. We then checked both batteries and found one was dead, but the good one charged. So now we will replace both batteries and hopefully our problem will be solved. Thanks for everyones input.

[skcyclist]

I recently had a similar problem. Turned out to be a 60 amp fuse blown in the fuse box in under the hood of the 1994 Ford. Fix is easy, trouble shooting is more difficult.

[Mike]

I think this thread demonstrates a couple of things. Davydd alluded to it, and markopolo mentioned it when he guessed your make and model farther back in the thread.
1) it really helps if you identify the year/make/model of class B your question is about. Any suggestions for what the problem might be are a guess at best, unless you narrow the possibilities by telling us what you're driving.The easiest way to provide this info is to update your profile. Click on "User Control Panel" from just below Board Index on the main page after you log on. Then click the Profile tab, and scroll to the bottom of that page, add your RV's details to the My RV box. Then click "Submit".
2) supplying, as completely as possible, any background history of any prior problems, or related prior repairs or replacements really helps, too. Even something you've noticed, that seems odd, can be a clue. When it comes to electrical issues, adding or removing things, like appliances, fans, lights, fuses, breakers, and any other stuff inside or out, can help others to better analyze the issue, or might just "ring a bell" and remind them of a similar problem with their rig.