Can you use a different battery?

[bunnspecial]

I have a car that was designed to run two 6V batteries in series.

Suffice to say, few if anyone even bother to do that anymore. The preference instead is to run a single group 26, which is only marginally larger than the spec 6V battery(so will fit in one of the battery wells designed for them) and usually gives ~200 more CCA than the factory set up(

 

[bunnspecial]

I have a car that was designed to run two 6V batteries in series.

Suffice to say, few if anyone even bother to do that anymore. The preference instead is to run a single group 26, which is only marginally larger than the spec 6V battery(so will fit in one of the battery wells designed for them) and usually gives ~200 more CCA than the factory set up(a bit over 300 on the factory batteries, usually over 500 on the group 26). Plus, you can buy them anywhere off the shelf and ready to go as opposed to having to order tar-topped batteries shipped "dry' and then filling them yourself.