Dual battery options in Ice Castle?

[Benjy]

I have a 2012 Ice Castle. The on board battery charging systems works pretty well, but I can already tell that in the second season of use, my battery life isn't what it was last year. I understand they wear down over time and need to be replaced. I'm wondering if there is a way to install a second battery along with some kind of switch that I could easily flip when I want to switch to the second battery. I would also want both wired into the charger so they can charge when I'm running my generator. I run my generator as little as possible, but on my last trip I noticed that my battery would not power my furnace all through the night on a single charge.

My other question is that I never really know when the batter is full charged, and wondering if there is an aftermarket product I could hook up that will tell me when its fully charged. I do have a volt meter that tells me the battery output, but to get an accurate read on that I need to shut down the generator or unplug on the outside. I don't want to mess around with that just to check charge - I'm looking for something that tells me when its charged so I can disconnect and be done with it. Any suggestions?

[whitebassman]

I run two batteries hooked in parallel in my Ice Castle.

Double the amps easily this way and still keep 12 volts. It works best if you have two new batteries at the same time, as the older battery will wear down the newer battery.

Make sure you don't hook them in series though.

[BuckSutherland]

Run two batteries at the same time. Problem solved.

[boxcar46]

I have to 6 volt golf cart batteries hooked together to make 12 volt. I only run my furnace on these. I have one deep cycle to run everything else. Battery tenders on them 24/7 when not out on ice. Never ran out of juice yet and they been in the shack since 2008...

[BLACKJACK]

My 2010 Ice Castle was set up with two sets of alligator clamps, one for the lights and one for the furnace, I bought the two biggest 12 volts I could find and a 3 bank Minnkota charger, mounted them all in the storage compartment under the bunk, when I get home I plug the house in with the outside plug, the lights on the charger go from red to yellow to green, tells me when they are completely charged. Had room so I added a third 12 volt battery as a spare, hooked to the charger also.

This setup gives me enough battery power for one night trips on the ice, haven't done any two night trips yet but when I do I'll run my generator for a few hours during the day to give them a little charge up.