2 6v parallel with 1 12v

[kfrenette]

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!

[MrWizard]

yes it can be done
not the perfect situation, but acceptable with 'low' amp loads
lights, 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

[Mandalay_Parr]

It's not ideal but it will work.

[Dennis_M_M]

All shall be revealed: The 12 Volt Side of Life

[skipnchar]

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

[RoyF]

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.