12 V battery duration?

[Undercover Poe]

Thanks, I’ll do that and wire them in series?

[woo10-210]

Before buying those batteries, research deep cycle battery maintenance and learn how to take care of them by proper charging and periodic equalizing. Your basic home charger can't accomplish this. There's a saying that batteries don't go bad, they're murdered. Running your battery down until it no longer runs your accessories is killing it. You should never run your DC battery below 50% state-of-charge which is about 12.2V. A flooded lead acid DC battery should last at least 5 years if properly maintained, usually more.

The Duracell DC batteries from Sam's Club are made by East Penn/Deka and are excellent but you wouldn't think so by reading the reviews. People don't know how to maintain them and kill them in a couple of years. Most manufacturers have changed their DC battery warranties to just one year because of this.

Read up on equalizing DC batteries. You may be able to bring some life back to your current batteries if they haven't been run dry.

[Undercover Poe]

I hear you. I’ve been a boater for 25 years and I thought I knew my way around deep cycles 12v. Or at least when my boat charged them, I knew what to do. I’ve had a battery last me over 12 years, removed it every winter, periodically charged it and if it sat in my boat for more than three weeks I’d hook a charger to it before we went out. Now with a camper, when I’m “Boon docking” it a different story. So how do you not let your battery get too low without a gen set? I guess start your car up.

I don’t mind spending $250 on a good battery set up. All I want to do is make it thru the weekend with having power for heat, water pump etc. I think I either got a bad battery with my camper. Or like you said. I
Killed it.

[woo10-210]

Originally Posted by Undercover Poe

So how do you not let your battery get too low without a gen set? . . . . . All I want to do is make it thru the weekend with having power for heat, water pump etc.

Solar. We spent Thanksgiving weekend in Lucerne Valley, CA (high desert) and the temps dipped into the mid 20's at night and never got above the mid-40's during the day. I only have two Centennial Group 24 flooded DC batteries and we easily made it through the night holding the furnace at 55° and the batteries were still at about 70% state of charge in the morning. I made sure I started the trip with the batteries at 100% SOC. A good digital voltage meter and a hydrometer are a must.

I was using two 100 watt solar panels running through a 40amp controller. These were set up as portable and I made a few adjustments during the day to keep them pointed toward the sun. I actually have five 100w panels that will be going on the roof in the next few weeks. More than enough for the two Group 24's but I'll be switching to a pair of 6 volts in the near future. The two Group 24's only give me 150 amp hours whereas the 6V's will give me 215.

You can set up a simple 200w portable system with a 40 amp controller for less than $300.

[SlowrideHD]

I would recommend that you find a golf cart shop and purchase two Trojan T-105 six volt golf cart batteries. They are 225 Amp and weigh 62 lbs each. Wired in series, you should get about 110 amps of use at 12.1 volts minimum which will be about 50% SOC. That's over 1300 watts of use before requiring a recharge.
As a reference, I get my Trojans for about $115 each from my local golf cart shop and they are never more than a month old off the shelf.