How would you add a second house battery?

[ctb]

Yes inside...under Goucho right behind drivers side w/vents just behind driver's door...keeps em' warm! Decided on two instead of one giant one!

[JebTN]

I am in the process of trying to add a second battery to my B and will probably go to two new AGM just because of the maintenance problems from the location I will have to mount the second battery.

I may go the route I did in a previous camper (non B) and just put in a switch and only run one at a time and switch when the first gets low. In that setup I only charged the one that was selected also, which made for more messing around but I didn't want to get complicated and we only needed the second battery a couple of times a year. In normal use I would just switch between the two batteries every so often to be sure they both stayed charged for when I needed the second battery. That also solved the problem of needing to have matched batteries. I did put in a switch that did Battery A only, B only, A & B in parallel or off, this gave me the option to use both at the same time if I ever got in sync and had two matching batteries. A secondary advantage to a switch was I knew when I threw the switch I was at the halfway point of power availability. One battery was under a bench and just had a closed (not sealed) box with an 1.5" hose going out the top to the outside. A normal lead acid battery will vent a bit of hydrogen when charging, AGMs only vent in failure mode as I understand it.

[basssears]

FWIW our van came from the factory with two batteries, one in a sunken box (so dropping from floor level to below floor level in a fiberglass containment box) in the right rear of the van and one under the gaucho in a vented box with a hose going to a vent on the left middle side of the van.


So we do have batteries that operate at different temperatures when it's cold, but haven't necessarily noticed a problem there. Once you start loading the batteries they will warm up on their own unless they're lithium. You will need to work out the voltage drop on wiring between two batteries if they are very far apart.


And definitely if you add a second battery buy two new batteries and retire the old one, don't add a new battery to the one that's already seen some use.


If I were to add a third battery (which I might, we almost always just boondock) I would put it under the gaucho right next to the second one and use the same vent hole for both battery boxes.


-- Bass

[simplesez]

Ok finished this project tonight. Got two new Duracell 27 AGM batteries from Sam's Club for $330. 0 gauge wire was $45, plastic battery box was $20 and miscellaneous pieces $10. So under $400 for a dual house battery. One battery is in under floor box and the other is inside the van.

Hope it does well this winter, that suburban furnace kills the power since my wife likes it toasty warm while camping.

Heading out this weekend. Already got a bunch of snow!

[BrianW]

I’m on my second set of Duracell 27s. First set of three lasted 5 years, and I’m not the best at charging upkeep. Got a new set of two this summer. I think they are a good value.

[basssears]

Originally Posted by simplesez

Ok finished this project tonight. Got two new Duracell 27 AGM batteries from Sam's Club for $330. 0 gauge wire was $45, plastic battery box was $20 and miscellaneous pieces $10. So under $400 for a dual house battery. One battery is in under floor box and the other is inside the van.

Hope it does well this winter, that suburban furnace kills the power since my wife likes it toasty warm while camping.

Heading out this weekend. Already got a bunch of snow!

Nice job! With the canvas of the pop top and the lack of efficiency on the suburban propane furnace you'll still put a good dent in two batteries but certainly big improvement over one.

[simplesez]

Yeah we don't pop the top with the heat on. We do pop it during the day to get the heat from the sun but the furnace is off. Benefits of skiing in Colorado versus the PNW.