[Archived]

If the idea is to make all leads the same length, then the right scheme is little better but I’d not call it “perfecty balanced”. This would require a large bus bar with equal length feeder wires to each terminal. Not worth the trouble in my opinion. Batteries themselves vary in their internal impedance, so they are never “perfectly balanced” even ignoring all external wiring.

Gerald

[Archived]

I think the ides is it’s pulling power from the middle from both ways?

[Gerald]

To be “balanced” ALL the cables have to be the same length. If one feeder cable is longer or has more connections it has higher resistance and will allow fewer amps to flow from that battery. But even if you get all the wires the same length, each battery has slightly different internal resistance which will influence how many amps it delivers in a parallel setup.

Pulling from the middle is better as you only have to go through 2 connections vs. 4 to reach the last battery but I would not call it “perfectly balanced”.

If in doubt I would stick with the way the coach manufacturer has wired the batteries.

Gerald

[Archived]

I don’t think it is bad to try for the optimum, but I am not sure the difference it would make would be measurable. I think this is especially true if you change batteries on a schedule as opposed to waiting for a failure. I have used 5 years as my schedule and never had an issue between changes. I would not guess optimizing the connections would give me another year of life so I think Gerald’s answer is just as valid as your reasons for wanting to make the change.

[Doug]

He difference in a perfectly balanced bank, equal cable lenght, etc is usually only a few millivolts. The batteries will vary more than that amount. As previously said, not worth the effort in our application.