Batteries in Parallel

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Dave_Rolfe

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I can remember seeing (some time ago now) a wiring diagram to show the best way to wire two 12v batteries in parallel to ensure that both of them received equal charge but cannot find the thread now.

Can anyone help provide the information please. It involved the +ve lead going to one battery with the -ve lead going to the other one but unsure of the connections in between.
 
If you are using large cable, 25 / 35 sq mm, don't bother, the volt drops are that small it will make no differance.

Brian
 
I think I know the diagram you mean but I can't find it either.

It was simply linking + to + and - to - but it made the point that you should take the main + feed/supply from the first battery in the chain and the the main -ve feed/supply from the last.

For only 2 batteries hardly worth worrying about.

(and yes that will give you 12V not 24!!)
 
If I wire them in series I have 24v, at least that's my understanding. I have fitted a Sterling Alernator to battery charger and was thinking the other day that I have just wired them with the two feed cables going to the first battery with 25sq mm cables to the +ve and -ve terminals on the second battery. I remeberered the diagram that I referred to but could not find it. As I have used heavy cable it would seem from Halcyons reply that I do not have a problem though. If it ain't broke, etc, etc.
 
[ QUOTE ]
If you wire them in parrallel you will have 24v .. ?? .. Are you trying to get a split charge circuit see HERE

[/ QUOTE ]

Parraell 12V, series 24V, assumung 2 12Vbatteries.
 
I remember that diagram too, but also can't find it! The upshot was that the cable length's were crucial, there was an equation too, giving scary numbers for load / charge distribution... For 2 batts, you are right... the +ve connection goes to one batt, -ve the other, with two short parrallel links connecting the batts. This kept the cable lengths the same, or something!!!
 
It was more about minimsing the drop due to the internal resistance of the battery. Wire length and resistance was treated as a constant AFAIR. The basic message was: do not take pos and neg feeds from the same battery, take one from the battery at 1 end of the chain and the other from other.

Assuming of course we are talking about the same diagram!
 
Re: Batteries in Parallel[Re. Venturerdave]

www.smartgauge.co.uk
Then click on Tech Info. across top
Then page 2
Then "interconnecting batteries" down catagories
Sorry I can't give direct link ------Excellent site !!!
 
Re: Batteries in Parallel[Re. Venturerdave]

That's the puppy. Well found.

This link should take you straight there

Finally, if you only have 2 batteries, then simply linking them together and taking the main feeds from diagonally opposite corners cannot be improved upon.

PS I use method 2 on a 4-battery bank as the pain/gain ratio for methods 3 and 4 is not favourable. ie the advantage of 2 over 1 is huge, thereafter each is a small improvement
 
Re: Batteries in Parallel[Re. Venturerdave]

That's the one. Thanks for your help and advice. I now have it clear in my head how to wire up for the optimum performance.
 
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