12 volt battery bank

[Ray Medland]

could anyone forward a diagram for balancing 6 12 volt batteries in parallel. II wanted to use method 4 that Smileypete used on the SmartGuage site.

[Tracy D'arth]

Just now, Ray Medland said:

could anyone forward a diagram for balancing 6 12 volt batteries in parallel. II wanted to use method 4 that Smileypete used on the SmartGuage site.

Its simple, connect them all in parallel then take the pos and neg cables off opposite corners of the bank. The aim is to get all the cables as near as possible equal length to every battery.

[Ray Medland]

Could you forward a diagram to that end, please?

[David Mack]

2 minutes ago, Tracy D'arth said:

Its simple, connect them all in parallel then take the pos and neg cables off opposite corners of the bank. The aim is to get all the cables as near as possible equal length to every battery.

That's not an exact balance, but is probably close enough for practical purposes.

[Ray Medland]

[David Mack]

4 minutes ago, Ray Medland said:

Could you forward a diagram to that end, please?

[Ray Medland]

I want to extend this bank to include 2 additional batteries of the same amp hour rating

[David Mack]

1 minute ago, Ray Medland said:

That's going to get complicated if you try to expand it to 6 batteries.

[Ray Medland]

thanks David but can it be done?

[MtB]

You are worrying about nothing. Just connect them all up in parallel however is convenient.

 

If one or two batteries do 0.1% less work than some of the others, it doesn't matter a jot. 

 

Its a non-problem. 

 

 

 

 

[Ray Medland]

Thanks MtB

I'm not 'worrying 'about it I just saw it as a balanced option and wondered if it could apply to a 6 bank system. If it's not going to be possible or too intricate then I'll go with the simplest of options.

[MtB]

59 minutes ago, Ray Medland said:

I'm not 'worrying 'about it

 

Oh good. We get a small trickle of new posters here worrying mightily about it, having gained the (false) impression it is critically important to connect up the batteries in a perfectly balanced way.

 

 

[IanD]

32 minutes ago, MtB said:

 

Oh good. We get a small trickle of new posters here worrying mightily about it, having gained the (false) impression it is critically important to connect up the batteries in a perfectly balanced way.

 

 

It's not *critically* important, OTOH the "diagonal connection" method is simple cheap and trivially easy to do, so why not do it?

[jonathanA]

1 hour ago, Ray Medland said:

I want to extend this bank to include 2 additional batteries of the same amp hour rating

 

I think the point of this is that you CAN expand it to 6,8 or whatever batteries.  by replicating the paired batteries.  I guess you could also do it as two lots of 3 for 6 batteries.  I think the advantage, if it is an advantage could soon be outweighed by the complication of all the connections (trying to get 3 fat cables on battery stud) or the need to use 'bus bars' for little discernible benefit as MTB says. Although gibbo made a strong argument for doing this. 

[Ray Medland]

thanks everyone for your help and positivity. Pardon the unintended pun.

[ditchcrawler]

The other way is a +ve and a -ve busbar with each battery connected to it with the same length cables 

[David Mack]

The theoretical advantages of the more sophisticated methods of wiring a balanced bank are always going to come up against the reality that nominally identical crimped and bolted connections are in practice going to have slightly different resistances, and method 4 with all its extra connections is just introducing more connections, and more scope for varying connection resistance. 

So the bank will never be truly balanced, whatever you do.

[Tacet]

Gibbo's calculations on working some batteries harder than others took no account that they would tend to equalise given time.

[Richard10002]

2 hours ago, ditchcrawler said:

The other way is a +ve and a -ve busbar with each battery connected to it with the same length cables 

That's how i have connected my 4 x Lithium batteries