12V or 6V

time2roll,

Either 4 lead acid--or 2 SiO2

Either way I recommend 4 batteries minimum if running a 2000 watt inverter anywhere close to capacity.

Rlw999,

thicker "plates" in 6 volt = higher resistance

Lower internal voltage in the 12 volt

double the number of cells, in 12 volt, so each cell has to produce only 1/2 as much of the current.

6v = 3 cells; 12v= 6 cells

x 2

6v pair = 6 cells; 12v pair = 12 cells.

My microwave draws 150 amps.

6 volt in series--each cell has to do 150 amps

12 volt in parallel--each cell has to do 75 amps

pianotuna wrote:
It depends what you wish to run. If you plan on a large inverter then 12 volt may be better.

Why is that? What's the difference between 2 6V batteries in series and 2 12v batteries in parallel for running an inverter? (I understand why putting the 12V batteries in series to get 24V would make it easier to feed a big inverter, but that's a much bigger project)

I recommend the 6v GC2 if you are spending money to have two batteries.
Most Costco and Sams club have good value GC2 batteries.

Hi,

It depends what you wish to run. If you plan on a large inverter then 12 volt may be better.

My next batteries will be SiO2 chemistry which have a much greater lifespan than lead acid. They are sealed and more or less maintenance free.

If one 6v battery fails you have NO DC for RV
If one 12V battery fails you still have 12V DC for RV

6V battery typically will have higher amp/hour then 12V
Two 6V is series...voltage doubles/AH stays same (6V/225AH=12V/225AH)
Two 12V in parallel...voltage stays same/AH doubles (12V/105AH=12V/210AH)

So Two 6V in Series will have slight advantage over Two 12V in Parallel

Do you camp without hookups? An energy survey will help you determine how many amp hours you need. Sixes are preferable to two 12s.

6 - 6volt batteries is a lot more than 2 - 12volt batteries (depending on specific models likely more than 3 times as much). Of course, it will cost and weigh a lot more also.

Assuming you meant 2 - 6volt vs 2 - 12volt, I would lean toward the 6volt option. 6volt golf cart batteries are true deep cycle batteries. Most dual purpose 12volt batteries really are built as starting batteries and get a different label. If you draw them down deep, they won't hold up as well as a true deep cycle battery.

The amperage draw from the 5er will be low enough that either can handle the draw. The 6volt option will likely hold more amp-hours and hold up to being drawn down better in the long term.