6 volt golf cart batteries

hollyp · #1 (**permalink**) 12-02-2007

Hi All, I'm getting ready to buy some 6 volt golf cart batteries to replace my worn out 12 volts. This bank is only used for my electric heads, lectra san, and shower drain. We live aboard so it gets a lot of use. My last bank was replaced about 2 years ago with two group 27 (?) 12 volt deep cycle marine batteries from NAPA. They worked perfectly until about a month ago when they were suddenly drained, probably because I let the water level get too low. I checked them monthly for the first year and they never needed water so I just stopped checking them. They are wired to a 12 volt smart charger that is also just two years old. I figured it's probably not over charging since the water level remained constant for the first year. I could be wrong. I'm wondering if there is any consensus about which battery is the best. I was thinking about costco verses interstate. Also, is there an online resource that can show me how to wire them together? Would I need two or four batteries? Thanks for any help you can offer!

Freesail99 · #2 (**permalink**) 12-02-2007

I just bought 4 interstate U2200 for $89.00 each.

sailingdog · #3 (**permalink**) 12-02-2007

Two 6V Trojan T105 Golf Cart batteries are going to be significantly higher capacity than a single Group 27 battery, so you really shouldn't need more than two.

As for wiring them together.. wire the positive of one to the load or positive bus for the head's electrical system, then connect the negative of that to the positive of the other battery, and finish by connecting the ground of the second battery to the ground bus of the head's electrical system. Ideally, you should have a panel of some sort with fused switches or breakers for the head, LectraSan and shower sump pump.

hollyp · #4 (**permalink**) 12-02-2007

Thanks for the wiring details. I do have a 12 volt panel dedicated to this bank so the wiring should go pretty smoothly. I guess I'll have to buy or borrow a big crimping tool to make the cables. The current bank consists of two group 27 twelve volt batteries so I guess I should replace them with four 6 volts?

sailingdog · #5 (**permalink**) 12-02-2007

Nope...A group 27 is about 100-110 amp-hours. Two would be 200-220 amp-hours. A T105 6V battery is about 225 amp-hours @ 6 VDC, so two of them are 225 amp-hours at 12 VDC, slightly more than two Group 27s.

hollyp · #6 (**permalink**) 12-02-2007

Excellent! I just saved some money!

sailingdog · #7 (**permalink**) 12-02-2007

I only charge 5% of what you saved...