Going from two 12 volt to Four 6 volt???

US Battery:

Hotwheelbill wrote:
http://www.modmyrv.com/2008/06/05/rv-6-volt-battery-upgrade

This link is not well balanced for heavy loads or charging as the main cables are biased to one side.

Search for 12 volt side of life .. Can't post a photo but I can a description.

First: I'm fond of saying "There are not six volt batteries in RVs" and now I will tell you why.

Take the first two Six volt batteries, Hook a jumper (At least auto starter cable) from the NEGATIVE on one to the POSITIVE on the other

Do the same with the other pair.

Now, you have two 12 volt batteries, same as you do now Connect to the remaining terminals exactly as you do the current ones, Ignore the already connected terminals connecting the two batteries.

or graphically

Two 12's

-Battery+
-Battery+

4 Sixes
-(bat)t(ery)+
-(bat)t(ery)+

(the "T" in the middle is the jumper. Each (**) is a battery, either six or 12 volt)

Think of it this way. Two 6 volt batteries equals 12 volts
Battery 1 negative terminal to battery 2 positive terminal. Reading battery 1 pos to battery 2 neg you now have 12 volts.
There are lots of diagrams on how to wire them on the net.