I need to replace my house bank, which is currently two Group 27s (~110Ah each when new, approximately 0 presently). So I'm looking at golf cart batteries.
I've been presented with an opportunity to buy four GPL-4CT (Lifeline Batteries - Marine & RV Deep Cycle Batteries
) used AGM batteries, two years old, that test out well, for $100 each (that's all I know; I don't know what sort of test or how many cycles, etc). These had 220Ah capacity when new, I'm not sure what they're at now. Would you do it? I live aboard, and mostly daysail, but at least once a summer go on a 3-5 day journey usually without shore power. I have a 40A charger and a 65A (?) alternator. Does this sound like an OK idea? I'm probably also going to sell my boat within 2 years (thought it was going to be this year, but likely not...), so I'm looking to not spend a ton of money.
The recommendation from the local battery dealer was Deka GC25s, new, for $170/ea. These have 235Ah capacity, so I only need two to replace my current bank, but I'd really like more capacity... I also really don't want to spend as much as four would cost, so all told if I went with this option I'd probably only buy two of them.
Cost and capacity both seem to be telling me to buy the AGMs, but if they don't last out at least two years, then it will have been a waste of money. What do you think?