House Battery Banks 2X6 volt vs 2 X12's

[WhiteNow]

Need all new batteries and was recommended by a boater that a good set up was using 2 X 6 volt batteries for the house 1 X 12volt deep cycle for Engine/Windlass Cranking.

The house theroy was that the two 6 volt house batteries run tandem

1.) have more amp hours .
2.) could be drained lower than 12 volt.
3.) they would recharge faster since they only have to go to 6 volt.

This system is commonly used in forklifts and golf carts where faster charging times are desired and longer running time and not a lot of power for cranking is needed.

 

[joker460]

Your Assumptions

1. They would have to be in series to give a total 12v and the amp hrs would be the same. ie 2 x 6v x 100AH in series would be 12volts @ 100AH.

2. You don't want to discharge any battery below 50%

3. Most Battery chargers are rated at 12volts not 6volts

 

[Maine Sail]

#1 True GC batteries pack more Ah for the foot print taken up than typical 12V "marine" batteries. The are also true deep cycle batteries meaning they will last longer in a cycling application.

#2 False..

#3 False..

See this link for more info..

What is a "Deep Cycle" Battery?

 

[centerline]

(2) 6v batteries wired in series will give you a 12v bank... it will NEED to be recharged with a 12v charger... (unless you have (2) 6v chargers and hook one up to each battery)

and im not disagreeing with any of the previous replies for practical use of the system, but theoretically there can be a safe draw down difference between (1) 12v marine battery and (2) 6v golf cart batteries, but its so small that it should not be considered into your decision to make the switch, nor should it be factored in to the planned usage of the batteries... just because it may be there is no reason to push the limits on purpose.
just be happy knowing it might be there helping your batteries to survive if they do get drawn down too far, too many times....

and even though forklifts and golf carts use the 6v deepcycle batteries, they commonly run on either 36v or 48v... some of them use 24v, but this is usually used on less demanding equipment.

but yes, you can benefit a lot by installing 2 quality 6v deep cycle batteries rather than the 12v marine battery that you may currently have...