adding 6v batteries to house bank, but 7 ft away

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mike_nickens1

Veteran Member
Joined
Sep 18, 2012
Messages
44
Location
usa
Vessel Name
Godspeed
Vessel Make
36" Marine Trader Sundeck
My house batteries consist of 4, 6 volt golf cart batteries. There is NO room to add more batteries at the current location. I'm considering add 2 more 6v at another location, but the cables joining them into to my house bank will be about 7ft to 8ft away. Not sure if this will be a problem. Any comments appropriated.
Thanks!
 
It can be done. The proper way to do it is to run the ground and positive cables from opposite ends (for example the ground from the 4 battery end and the positive from the 2 battery end) as it will keep the banks closer to balanced.
 
In a perfect world all 6 batteries should be together of the same make, model, and new when put together as a bank.

I assuming these are in series and parallel to make 12 volts. So you have 3 sets in parallel of 2 batteries in series. When wiring the 3 sets in parallel, you want the 1st set to have either the positive for the bank attached to it. The 3rd set gets the negative for the bank. This is done so the batteries feed and charge uniformly. So you will have to move one of the bank feed wires over to the 2nd location.

Finally, the battery cables (8' long) between the 4 batteries and the 2 others will need to be larger than the ones between the group of 4. I would guess 2 wire sizes larger too minimize resistance and voltage drop.

Failing to do this properly with have a dramatic impact on the effectiveness and longevity of the additional batteries.

Ted
 
Mike,
Do you by any chance have additional height where current battys are located?
There certainly taller battys that provide additional AH when compared to GCs.
 
Agree with what others have said. Downside may be that batteries won’t be equally charged. So would emphasize previous recommendation to make the 7’ interconnecting cables large, perhaps 4/0, or even parallel 4/0.
 
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On our last boat I wanted to do the same thing. Not enough room for the extra 2 batteries unless I got rid of the A/C compressor in the engine room. That would have been about $2400 for a new A/C plus all new batteries, 6 of them. It ended up cheaper for me to go to 3 105 AH LiFePO4 batteries. I even bought a 120 amp Balmar alternator and smart regulator and still saved money. The Lithium batteries do have some quirks but they last forever and can take a huge charge rapidly.
 
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