TomG2 wrote:
My four month old camper came with a dual purpose marine battery and I want to increase my electrical capacity. I realize that dual purpose is not the best choice, but should I pair it with a true deep cycle or purchase a matching dual purpose? I am not ready to throw away a four month old battery just to get two six volt models as I don't boondock that much. Thanks.
Finding true Deep Cycle in 12 volts may be ... hard to do.. (yes they do make them) may also be expensive.
Consider, if you have the head room, a pair of GC-2 Golf Car batteries (Which by the way brings up a suggestion as to where to look for deep cycle 12 volt,, golf car battery stores).
These half-12 volt batteries (Think of them that way) hold 220-230 (Some as much as 250) amp hours... They are true deep cycle and when you wire the two of them in series they basically become one 4D size 12 volt battery DEEP CYCLE type.
Treat them like that
Some numbers
Group 24, about 75 HA at the C/20 rate
Group 27, around 95, Group 29, around 105 and
Group 31, around 130
4D and 8D 220-270 depending on speciics.
Weight per amp hour at 12 volts.. Nearly identical across all sizes.
GC-2 six volt pairs in series,,, 220-230 amp horus
All ratinggs are +/- about 5%