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GravelRider's avatar
GravelRider
Explorer II
Jul 05, 2020

Switching from 12 volt to 6 volt batteries

After our third time out dry camping with our new travel trailer, we started running into battery bank issues. Our first two times out, we had no issues at all with running down our battery bank overnight while dry camping. We added a television to the camper (which we fell asleep watching! Doh!) and used heat for the first time overnight and ended up in the morning with our voltage reading at 11.4 volts. To be fair, our 12 volt fridge was running at the time, so I'd imagine actual voltage was probably 11.6 or so, but still too low for my tastes, and for good battery longevity. Granted, better discipline would have avoided this, but it got me thinking about adding some more capacity. And yes, I know, better discipline is the right answer here... But I like overkill... lol

I have two 12 volt 81 Ah batteries (which I thought were 100 Ah when I bought it... as the dealer said the 'upgraded' batteries were around 100 Ah) for a total bank of 162 Ah. I had looked into adding two more 12 volt batteries in the 75-100 Ah range, but that ends up being a lot of extra weight at the front of the trailer, and finding space for them would be an issue. So, I'm now thinking of swapping out the two 12 volt batteries for two 6 volt batteries wired in series. This would give me 450 Ah, which would likely be far more than I would ever need, and I would probably never discharge near 50%. ****EDIT, nope! 225 Ah!

I'm looking at this battery and this box, which would only add about 50 extra pounds.

Anyhow, besides the battery boxes and series wiring, would I need to do anything else? Like add a different converter or anything?

FYI, my trailer is a 2021 Indian River 22MKSE with a small 50 watt solar panel factory installed (which I really only use to keep the batteries trickle charged when stored).

76 Replies

  • KD4UPL wrote:
    When you connect batteries in series you add the voltages but not the AH capacity. 2 of those batteries will only give you 225 Ah at 12v. It's a significant upgrade from what you have for sure.
    If it were me I'd go with standard wet cell golf cart batteries. They will be less expensive but you will have to keep tabs on the water levels.


    Whoops! I was hoping to edit this before I got replies. Yes, of course my amps don't double in series. My old college physics professor would be shaking her head if she read this post. It's the 4th of July, and I may be having a couple beers. lol
  • You're gonna get a lot of opinions on this one. I like 6v cause you have a better chance of getting a true deep cycle battery with a 6v. It seems to me you can get 235 amp hours from 140 pounds of battery. With 12v you can get 200 amp hours but I think it'll be a few pounds heavier. There are true 12v deep cycle batteries are out there but they're not as easy to find. I'd never buy a 12v "deep cycle" from a local vendor unless they only sell batteries. Trojan are great. I think Deka's are great. Deka's are marketed under the Duracell name also. Duracell batteries are marketed thru various vendors, Batteries Plus Bulbs is the one I got mine from. Thinking I'm two years into them and still perfect. You'll need some kind of recharging ability in your coach if you plan to continue boon docking. I recommend as stout solar set up. I have yet to need to fire up my generator and I use what ever I want, whenever I want. I run 4-6v batteries.
  • Yes, you need to fully recharge all your batteries every day. Easiest way is a solar system. Further you are throwing batteries at the issue. Guessing. Do an energy use survey to determine what you need. Why run your fridge on 12 volt? Propane cools better and uses very little electricity.
  • https://www.atbatt.com/how-to-wire-6v-batteries-in-series-or-parallel-configuration/

    OOPS!
  • Don't know how to do the "clicky" thing, but you might want to check out this link.
  • When you connect batteries in series you add the voltages but not the AH capacity. 2 of those batteries will only give you 225 Ah at 12v. It's a significant upgrade from what you have for sure.
    If it were me I'd go with standard wet cell golf cart batteries. They will be less expensive but you will have to keep tabs on the water levels.