6v vs. 12v house batteries

For me the answer comes down to weight. A given battery is going to weigh a certain amount per amp/hour per cell. A deep cycle battery with a decent amp-hour per cell rating is going to weigh around 75 lbs for a 6 volt battery and 150 lbs for a 12 volt battery. I have both, and I much prefer installing the 6 volt batteries...

I have 6v deep cycle US2200 at 232 AH, and some 8D 12V start batteries (not deep cycle) at 245 AH. I need to stretch and do deep breathing before I install the 8D's...

Brian