One Battery is shot -- 4 of 6 cells are dead -- question on replacement?

[FrankO]

The house batteries are 12V 2 of each and the chassis is a single 12V. One of the house batteries will not hold a charge so I tried everything I can think of and things I have read and it will not come to life. I did a Hydrometer test and found 4 of 6 cells dead. The second battery is great and will hold a charge at about 12.32 V. The batteries were ne a year ago when the first owner bought the MH. It sat on the used MH lot for 4 months which probably did it in.
Now my question: Can i get away with replacing one of the 12V house batteries or do I have to replace both. I asked an Interstate Battery rep about 6V Golf Cart batteries and he said I would be much better of replacing both 12V batteries with 2 6V GC Batteries in series. What are your opinions/experiences on this?
Thanks -- Frank O.

[FrankO]

The house batteries are 12V 2 of each and the chassis is a single 12V. One of the house batteries will not hold a charge so I tried everything I can think of and things I have read and it will not come to life. I did a Hydrometer test and found 4 of 6 cells dead. The second battery is great and will hold a charge at about 12.32 V. The batteries were ne a year ago when the first owner bought the MH. It sat on the used MH lot for 4 months which probably did it in.
Now my question: Can i get away with replacing one of the 12V house batteries or do I have to replace both. I asked an Interstate Battery rep about 6V Golf Cart batteries and he said I would be much better of replacing both 12V batteries with 2 6V GC Batteries in series. What are your opinions/experiences on this?
Thanks -- Frank O.

[03 CORVETTE]

same thing happened to me if your keeping the bus like me i put in 2 optima agm batteries pricey but they have been in there 18 months first ones lasted two months dealer said the were overcharged becaused im plugged in at storage two months later they changed convertor under warranty never got paid for batteries.......

[Harry B]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Battery rep about 6V Golf Cart batteries and he said I would be much better of replacing both 12V batteries with 2 6V GC Batteries in series. </div></BLOCKQUOTE>

Frank, I would agree with them on replacing both 12v batteries, as battery life is best maintained when you have a matched set of batteries when they are connected in parallel.

If you decide to go the 6V route and you currently have 2x 12v batteries you will need 4 6v batteries to equal or exceed their capacity.

[John_Canfield]

I share Harry's opinion. You can get by with replacing only one battery but that just sets you up for trouble later on when the older battery decides to cause trouble. Since you have two batteries in parallel, trouble on one battery means trouble on both batteries. The good battery could discharge into the battery with bad cells. It's just not worth the hassle that will happen later.

About 4x6V batteries - it's all about ampere-hour capacity. The 6v batteries probably will have more capacity that the 12v, but you need to look at the battery specifications. When you do the math, remember it takes two 6v batteries to make 12 volts so you only count the ampere-hours of one 6v battery when adding up the capacity. For example, assume each 6v battery had 200 ampere-hour capacity. The total ampere-hour of a bank of 4 batteries would be 2*(200) or 400 ampere-hours.

[Y-Guy]

Good advice has already been given, just wanted to pass along a good website for battery info. I've used it and referenced it many times - The 12volt Side of Life

[FrankO]

Thanks all for the advice. I read the info posted and talked to a "Battery Guy" who is in the business. I wound up replacing the 2 12 Volt RV/Marine Batteries with 2 Golf Cart (6V) batteries as the rating (Amp Hours) is 75 is superb to the 2 12's and life expectancy is up to 8 years if you take care of them.
The RV/Marine batteries which were installed with the MH are just not up to snuff. If I could put 4 GC batteries in I would but I have limited room. I also am looking at the Trik-L-Start to keep the Chassis battery in good shape.
Any opinions or first hand experience?
Thanks -- Frank O.