Batteries in parallel

[Achilles]

I'm not entirely sure that I've connected my batteries together in the most battery friendly way and would appreciate your advice.
I have a house bank of 3 X 100amp hour batteries connected in parallel, the last battery in the chain being connected to the 1 2 ALL switch and subsequently the instrument panel. Question is should I have the postive from the bank connected to the first battery in the chain and the negative from the bank connected to the last battery in the chain? Would this provide more all round usage of the batteries and possibly longer life?

Thanks

 

[CaptainBob]

If they're connected in parallel, then there is no chain. Are you sure they're connected in parallel?

 

[colinmi]

Makes no difference.

Although standard practice to connect the out going pos and neg cables to the same cell and at one end of the battery.

Cheers Colin

 

[DinghyMan]

This explanation of Peukert's Equation (Peukert's Law) was posted recently which shows how to wire batteries in parallel - as you say positive from one end and negative from 'topposite seems right.

 

[Achilles]

Yep they're connected in parallel. They are simply 3 batteries in a row which I've called a chain, and I'm asking if it's better to have the postive cable connected to one end of the row and the negative to the other end.

 

[CaptainBob]

Ah OK, comprendez, then I agree with Colin, makes no difference whatsoever - as long as your connecting wires (between each battery) are of the appropriate type (ie very thick, low resistance) and the connections are all sound.

However, if you take the output of ALL batteries as one into the 1/2/Both switch, you're turning it simply into an on/off switch for the whole bank, rather than using it as intended.

 

[Achilles]

Thank you and agree with what you say about the switch. I omitted to say I also have an engine start battery.

 

[pvb]

The correct answer...

[ QUOTE ]
Yep they're connected in parallel. They are simply 3 batteries in a row which I've called a chain, and I'm asking if it's better to have the postive cable connected to one end of the row and the negative to the other end.

[/ QUOTE ]The correct answer is yes. By wiring as you've suggested, any tiny resistance in the connections gets cancelled out and all the batteries should get the same charging voltage. I have 6 batteries in parallel in my domestic bank, and the pos & neg are connected to opposite ends of the bank.

 

[Achilles]

Re: The correct answer...

Thanks everybody, your help is appreciated.

 

[jmh2929]

Re: The correct answer...

This was discussed a while ago read this

 

[jennymckay]

Ditch the 1-2-both switch for dedicated on-off battery switches for both domestic bank and engine starting battery, and fit an emergency parallel switch to join the 2 banks together.

 

[Achilles]

Re: The correct answer...

thanks, confirms what others on this thread have said. Do I assume that inputs from the battery charger, alternator and solar power also go to the positive terminal on the end battery and the negatives to the other end battery?

 

[Achilles]

How does this help? Doesn't switching my 1 2 ALL switch to ALL achieve the same thing?

 

[jennymckay]

The whole point of separate batteries for domestic & engine duties is to keep them seperate. The 1-2-both switch allows everything to come off battery bank 1 or 2 or both, so when (not if!) your domestic batteries go down, you will have to put your engine battery in parallel to keep everything running. Next day, you will not be able to start your engine.
If you intend to live aboard, this is a subjecy you MUST research.

 

[jmh2929]

Re: The correct answer...

Yes that's the way I read it. /forums/images/graemlins/ooo.gif