Originally Posted by B_and_D

We started out with a group 24 battery, it didn't last long (came with the TM when we bought it used).

We bought 2 6-volt Trojan T-105's the next spring. We've had them for 5 years. They only charge up to 12.4 volts now, max, but we went camping w/o hookups this summer for 6 days and they were still at 12.2 when we left camp. We only used them for the lights (sparingly), toilet (at night) and water pump in camp.

We bought a 12 volt group 27 battery from Costco when we were in Palm Springs 4 years ago last January. It still charges up to 11.6 or so, but I bought a new one before we went camping this summer to run the DVD player and TV. That group 27 battery was a real workhorse, it would charge up to 12.9 and lasted us for up to 10 days with minimal charging, only using it for the TV/DVD. It didn't cost that much, I think the new one was about $80. The old one is just sitting outside now, and it still had enough power to pump up our tires with a 12v compressor before we left for the Petaluma rally after being charged a few months ago.

That said, the Trojans are still holding way more voltage than the group 27 battery, and I wouldn't hestitate to take them camping again. We recently bought a Honda 2000 but haven't had the chance to use it camping. If we didn't lose our power here at home so often (hoping it doesn't happen tonight, what with 45 max winds predicted) I'd have purchased a Honda 1000 for just recharging the batteries.

My conclusion is:

We love our Trojan T-105's, they are very long lasting and hold a lot of capacity. I might buy new ones after next summer, if they don't charge up to 12.4 or so.

The $80 Costco group battery we bought lasted very well for 3 years, but then it didn't hold a charge that well after that.