Seeking More Running Time
Posted: April 1, 2012
Accessories
I have a 2007 Rinker 280 Express Cruiser with 12v starting and house batteries. I replaced the house battery with a pair of 6v batteries wired in series, which lasted longer when I used the lights, TV, etc., but now it’s time to replace them. Would I get even more running time if I use a pair of 12v batteries wired in parallel? 
The running time shouldn’t change as a result of wiring in series; this is more a function of amp hours, which could be higher or lower depending on what your batteries are rated for. If you get a pair of 12v batteries and wire them in parallel, you’ll double the amp hours available to you, but if those batteries are only rated to half that of your current 6v system, there will be no change in running time.