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Dead cell in Coach Battery


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My RV (Jayco Greyhawk 31 FK) is usually plugged into a 30 amp outlet while parked at our house. i recently unplugged it for a couple of days due to extensive flooding in our area. At the RV the water level was about six inches deep so not too bad. During that time I noticed that the coach battery was not holding charge as the coach lights (all LED) began to dim rather quickly. This battery is an Everstart brand, just over a year old, purchased at WalMart in Arkansas.


Using a Greenlee AM-6 voltmeter I got a voltage of less than 11 volts on the coach battery. The rig was plugged back into the 30 amp outlet and the coach battery charged through the Magnum MS-2012 inverter/charger. After the charger showed that it had switched to float mode I disconnected the 30 amp cord, waited until the next day and then checked the voltage at the coach battery. It was again down to below 11 volts. I again plugged it into the 30 amp outlet and waited until the charger showed that it was in float mode. Then I used a hydrometer to check the specific gravity and found that while most cells showed specific gravity of 1.3 or more, one cell was less than 1.1. In other words the specific gravity in one cell was not even on the scale. I have been using the equalization cycle of the MS-2012 for three hours now and there has been no increase in the specific gravity of the subject cell.


Any ideas of why this would happen on such a new battery? If the equalization cycle does not fix the problem is there any way to save this battery?

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If your battery is the one I think it is?? I AGREE its NOT a true Deep Cycle such as say a Trojan Deep Cycle Golf Cart Battery, however what I consider a semi or quasi RV/Marine Deep Cycle. I believe those batteries are intended more for somewhat dual purpose in they have sufficient Cold Cranking Amps to start a relatively big marine outboard engine, but thereafter operate more like a deep cycle to power a trolling motor. STILL THATS NO REASON FOR A CELL TO GO BAD.


I also wouldn't hold my breath any equalization or high current recharge effort will cure a bad cell and if it doesn't its back to wally World for whatever warranty exchange they will grant you.


For what I consider true deep cycle applications (such as typical RV use) I prefer a full true deep cycle battery versus an RV/Marine semi deep cycle dual purpose (starting then trolling) battery like sold at Wally World. Of course that may require the use of two 6 volt units in series if you have room for such combination???? If not Trojan and others make true deep cycle batteries in 12 volt, but they are pricey. Still if Wally World gives you a good warranty and/or if you only have room for one battery that will get you by AND I DOUBT THE FAILURE WAS DUE TO YOUR QUALITY MAGNUM CHARGER and I don't know how much time it may require in the equalization mode to cure a problem, but doubt your bad cell will come back to life regardless.


Your money your choice


John T

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I would check the MFG date. No telling how long that particular cell might have been sitting on the shelf with little to no charge before you bought it. One possibility anyway. Another might just be impurities in the compressed mesh plates during production. Contaminants in the electrolyte. Poor/fouled internal connection.


You won't be able to swap it out for a true deep cycle though (on edit: If you have multiple cells that is). Ideally, you'll want to swap it out for the same type and size.. hopefully under warranty.


When you're ready to swap out the entire bank I agree with John on going with true deep cycle batteries. I wouldn't even think to consider your Mag as suspect is this case. Just a dud cell.

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Actually the battery in question is a Marine/RV battery. I knew when I bought it that it was not really what I wanted, but the previous OEM coach battery had died while we were on the road. It was a weekend and only Wally World was open. We usually do NOT shop at Wally World anymore even though I grew up in NW Arkansas where WalMart headquarters is located.


No, the inverter was never used with just this one little battery. The Magnum inverter was used to replace the OEM Xantrax inverter that never worked right. It did, after all have only one little battery. We also used the Magnum to replace the converter. The only loads placed on the battery over the past year that we have had it was mostly to run the interior LED lights. Most of the time the RV was parked and plugged in at a park or at home. The battery is just faulty. The Jayco Greyhawk does NOT have enough room to place a larger battery let alone a second battery.


To solve this faulty battery problem I have made a new battery box in the large basement compartment under the bed at the rear of the RV. I have placed two Lifeline GPL-8DL AGM batteries (recommended by Jack Mayer) in that compartment. They are large, heavy and very expensive but have 255 amp/hours each. A MorningStar TS-60 MPPT charge controller is now installed and four solar panels are next. I just have to clean and recoat the rubber roof first.


Thanks to all for the replies.

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I have placed two Lifeline GPL-8DL AGM batteries (recommended by Jack Mayer) in that compartment. They are large, heavy and very expensive but have 255 amp/hours each. A MorningStar TS-60 MPPT charge controller is now installed and four solar panels are next. I just have to clean and recoat the rubber roof first.


Excellent! That'll keep you going awhile. ;) Have fun!

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