Did I fry my house batteries?

[neo102470]

I bought a used Fleetwood Storm 30H (class A, 30ft) motorhome from a mechanic in late June. He stated that he did all the routine maintenance on it every fall - oil changes, chassis lube, etc. I made the mistake of assuming that he had also filled the house batteries with water...

When I was winterizing it, I used over 6 QUARTS of water to fill my 2 12V Interstate house batteries... After I used nearly a gallon in the first one, I could see on the outside of the semi transparent case that the water was only about 3" deep in the other one. We've never boondocked and have always had shore power and don't have an inverter so we've never taxed the house batteries.

I have no idea what kind of charging system I have. I haven't actually found the house battery charger yet...

Are these batteries fried since the plates were not submerged and I doubt the PO ever checked or filled them?

Finally, what's normal water usage in a unit that is never boondocked?

THANKS!

[NLOVNIT]

I would say your batteries are toast. Even when unplugged from shore power, with everything turned off inside, there's still parasitic loads drawing on the house batteries.

Our coach stays plugged to shore power 24/7/365, even during winter storage. With the exception of 1 year - I forgot to connect the power cord after we put the cover on (solar charger doesn't work when covered by the RV cover), had left the radio on, the batteries got drained & split - we've not put anymore than a cup or so of distilled water in our batteries in the 4 years we've owned our coach.

Lori-

[Poptop]

The batteries probably won't hold a charge for you now but at this point you don't have much to loose if you try them anyway. The charger is probably part of the inverter somewhere inside the coach, or maybe its in one of the outside compartments. The batteries will be charging as long at the coach is plugged in to shore power (if it works correctly). The amount of distilled water you need to add depends on how long/much the charger is running and other things (i.e. in hot and/or dry weather some will evaporate through the vents.

[RV Wizard]

Here are some additional links of information about batteries that, for those serious about them, will find useful. Be aware that when you "equalize" that the inverters are using a high voltage for a long period of time and you may want to disconnect your appliance controls from this circuit during this time; I do. It is a good time to defrost the refrigerator and do other maintanance.
U.S.Battery/Leader in Deep Cycle Batteries
Frequently Asked Questions (FAQ) - DC Battery Specialists
Deep Cycle Battery FAQ
http://www.rvsolarelectric.com/sources.htm
http://www.batteryfaq.org

[Monacoach]

Fully charge your batteries then use a hydrometer to test the cells. If you have a dead cell and don't replace batteries you could do damage to other components such as the isolator relay. If all the cells show similar gravity you may be OK.

[Poptop]

Good battery information RV Wizzard, I book marked them for further reference.

[neo102470]

Thanks for the feedback. Great resource info!

I checked the batteries yesterday after being hooked up to shore power for the 5 or 6 days since I filled the battery water and the batteries each read ~6.6V after I unhooked shore power (I was mistaken in my original post, they are actually 6V batteries wired in series so the house sees 13.2V)... This seems a little high based on the info that RV Wizard posted.

Your thoughts?

[RV Wizard]

13.2 vdc on a full battery bank is fine. you could even see this voltage on a charged bank if the surface charge has not been drained off.

[Dave Rickey]

I'd watch how they do at holding a charge, but it sounds like you dodged a bullet. If they're 6V in series, then they're probably "golf cart" batteries, which tend to be built better than ordinary RV/Marine deep cycle batteries, more tolerant of true deep discharging. I had a similar experience with the Trojan 6V's in my Rialta, they were left sitting for nearly a year, drained completely dead, and I figured they were a write-off when I bought it. Much to my surprise and delight, they came back after a day on the road and seem to be doing just fine.

--Dave