Hey Guys, I am new to RVing and I we have just bought a jayco x213. My family and I are doing our first dry camping and I have purchased 2 6v batteries. My question is this, will I run into any problems hooking the 2x6v (already in series) parallel with the 12v. They are different batteries. Should I just keep the 12 as a back up and run the 6v? Any recommendations would be great!

I've never done it, but I would certainly want the two 6v in series and the one 12v to have the same voltage reading, or as near the same as you can get as measured by a good digital voltmeter.

It will work but not be efficient. For maximum efficiency all batteries used in parallel should be the same size, power and age. When any of those things are mismatched efficiency drops. Charging may be incomplete and they will discharge faster than optimum. Weaker batteries in the group will drain the stronger ones down to their level.Good luck / Skip

All shall be revealed: The 12 Volt Side of Life

It's not ideal but it will work.

yes it can be donenot the perfect situation, but acceptable with 'low' amp loadslights, fan, water pump, etc..using an inverter with high wattage loads, is where the difference in battery design and age will have a more noticeable effect

2 6v parallel with 1 12v | Good Sam Community

mlts22
Explorer
Jul 05, 2013
There is always getting a four position (A/B/A+B/off) battery switch, so you can keep the battery banks isolated, or if you want, use them together. That way, they can be charged separately from each other.
kfrenette
Explorer
Jul 05, 2013
Thanks everyone. I ran the set up on our first dry camping trip and it was great.
marbil_146
Explorer
Jun 24, 2013
X3..I have exactly that all wired in together with two Blue Sea switches two separate solar systems one roof top one portable with separate Morningstar controllers.
I can have both charging together or separate.....I just completed a 17 day test in two B.C Provincial parks under varied weather conditions and was pleased to find that the battery's worked well together and even the two controllers seemed to talk to each other.
With 150 watts portable and 213 rooftop flat I was in regulation by mid morning and float in early PM and that's with approx. 100 amp hrs daily use.?...50 for one week,portable Engle freezer.
The two battery banks are new so that might help but any time I isolated one from the other I always came up with an equal voltage reading......I ended up just charging and using both together as one big 330 ah bank.
Hope I'm not hijacking this thread with my ramble.
mena661
Explorer
Jun 24, 2013
smkettner wrote:
No damage will occur. You will just have more power.
X2
time2roll
Nomad
Jun 24, 2013
No damage will occur. You will just have more power.
kfrenette
Explorer
Jun 24, 2013
Well I have a box built on the front, and hooking in parallel is pretty easy with it. I just didn't want to cause any damage to the 6v or the RV by running it in parallel.
OnaQuest
Explorer
Jun 24, 2013
Carrying around a spare battery, in a box, NOT hooked to a charging source is like carrying a spare tire with no air it it. What good is it going to be when you decide you need it?

If I was going to keep it at all, I would hook it up in parallel with the two 6s (with jumper cables) after I got set up in camp and then remove it when ready to leave.
RoyB
Explorer II
Jun 23, 2013
I'd carry the 12VDC battery in a battery box as a spare in the back of the truck.. Will be a great PLAN B....

Roy ken
kfrenette
Explorer
Jun 23, 2013
Thanks everyone. I think I am going to go with the 12v as being a spare.
time2roll
Nomad
Jun 23, 2013
While in use or on a float charge they are fine. Otherwise I would separate.