# Multiple Leisure Batteries



## 89862 (May 1, 2005)

Our Burstner has 2 x 110Ah leisure batteries which are ageing gracefully. We'd like to up that to 4 x 110Ah, which begs two questions:

1 Can the old & new batteries peacefully co-exist, or will we need 4 new ones (gulp).

2 How far apart can the batteries be? The 2 existing ones are side by side, but the 2 additional ones will have to be mounted at least ½ metre away.


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## DABurleigh (May 9, 2005)

"1 Can the old & new batteries peacefully co-exist, or will we need 4 new ones (gulp)."
I would entertain switching of the 2 banks of 2, old and new, especially if you are entertaining 4 batteries for duration as opposed to high current applications. However, if you don't want to switch them, or you do want to use high current applications (where terminal voltage otherwise may drop too low in cold temperatures) then personally I would have 4 new, matched, batteries.

"2 How far apart can the batteries be? The 2 existing ones are side by side, but the 2 additional ones will have to be mounted at least ½ metre away."
Keep the cables joining the two sets of two (if in parallel and not switched) as thick as possible (as in stiff welding cable thick), and take the feed off the negative of one set and the positive of the other set. If routing the joining cables through a bulkhead, or anywhere there can be contact with the cables, then fuse them at the batteries.

Dave


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## Jean-Luc (Jul 21, 2005)

Hi pmorand, ALL batteries should be in the same condition, ie, same age, same size, same state of health.
Distance between the batteries in of no consequence so long as the interconnecting cable is of sufficient size for the load/distance between them.
BTW why four, a charger like the Stirling B2B will put in the region of 50% more charge into a battery than the standard kit fitted by the MH manufacturer and also works best with 'wet' batteries avoiding the expense of buying gel or AGM for example.
Have you considered the extra weight involved.


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## clodhopper2006 (Aug 13, 2006)

just to add that with a cable length of half a meter between batteries you should fuse the leads at both batteries to prevent either battery shorting in the event of the cable being cut.


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## DABurleigh (May 9, 2005)

I'll save Clive's job for him 
http://www.motts.org/second leisiure battery.htm

Note the feed length is equidistant to both separated batteries. At high currents or insufficiently thick cables, this is important, for the same reason as I said take the feed off different terminals (this presumed that for 0.5m separation you wouldn't have separate earth cables).

Dave


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