2 12 volt batterys or 2 6 volt

Two 6 volt batteries are a better choice for "house batteries".

Six volt batteries have three cells, which are larger with thicker plates than a 12 volt battery, which has six cells. So, the 6 volt battery will tolerate discharging and charging much better than the 12 volt.

Starting batteries should be 12 volt, even if you have two as most diesel pusher coaches have. They work better as they provide high amperage for a very short duration and then are recharged.

I often hear that people dont have good luck with group batteries. I have 4 of them from Sam's club wired in series powering a 48 volt pontoon boat motor. They are charged with a lester industrial type real battery charger that goes to 61 volts on each charge. Thats 15.25 volts per battery. They have sat in storage every winter for 7 months. The last 2 winters I did put a battery tender on them. Wired parallel of course.


But I do have four 6 volt Sam's in my RV. I dont know if 12 volts could stand up to my RV use. I have worked these 6's hard for 2 years and wouldn't blame them if they died now.

The boat gets far less deep discharges so their life has been easier. But I'm extremely happy with 8 years. I'll see what happens when I install them in next spring.

Two six volters from Costco.

I have not had very long life with 12 volt batteries, but my first set of 6 volts lasted 13 years, and I gave them away, because they where still good, I was just starting a 2 year long trip, and wanted new batteries.

My second set only lasted 6 years. Most I got from 12 volt coach batteries was about 3 years.

When they go bad, I would change them back to the factory 6 volts that came with the unit when new. Someone changed them to 12 volts at some point.

Good luck,

Fred.