Check me on this- Atypical battery parallel setup

[Mattb4]

I am thinking of creating a common bus bar battery parallel setup. What I am thinking of doing is wiring two batteries in parallel with short equal size cables between and from them a set of output cables to terminal blocks with the positive to battery 1 and negative to battery 2. There will be 3 sets of paralleled batteries (6 batteries) for 3 each terminal stud hookups with a 4th terminal lug as connection to my AIO.

As far as I can figure this should be about the same as if all 6 batteries had their own wires from the bus bar. Am I missing something in my thinking?

 

[Hedges]

And inside a battery (of some types), there are many electrodes connected in parallel.

Yes, I think two batteries paralleled with wires off the corners is a way to balance, looks like one bigger battery.

Three batteries with identical cables to a busbar is pretty much balanced, except for resistance of busbar. Short, thick, connections to load taken from opposite ends should make it good enough.

I've connected ring terminals one on top of busbar, one on bottom, bolt through, as a way to make busbar shorter.

Three is such an odd number. Four or Eight and you could have extended the "diagonal corner" concept.

 

[Mattb4]

...

Three is such an odd number. Four or Eight and you could have extended the "diagonal corner" concept.

Many of the pre-built battery bus bars available have 4 terminal connections. The price rises fast the more connection lugs they add. A lot of that is they suppose a higher amperage is going to be needed instead of just needing extra points of connection.

Not sure that putting 3 batteries in parallel instead of the proposed 2 before wiring to the bus would allow a 4 terminal bus block to work with 9 batteries sets in parallel but it might be the limit of this method.

 

[Hedges]

I think better to put 2 (or a power of 2) batteries in parallel with cables, then use busbar to parallel random number of those. Cables are long and skinny, busbars can be short and fat. If 8 batteries, multiple ways to exactly balance resistance.

You can get copper bars and insulated standoffs from McMaster, or copper at lower price from Online Metals. Sometimes used deals on eBay.

I connected one string of batteries to four inverters using three holes. Battery to center hole, inverters top & bottom side of bar outer two holes.

 

[Mattb4]

...

I connected one string of batteries to four inverters using three holes. Battery to center hole, inverters top & bottom side of bar outer two holes.

Hmm... I had not though about multiple AIO's. I suppose that depending on costs additional bus bars for connecting them together before connecting to the battery bus bar would work if going the pre-built route.

Eventually I will have to get all this incorporated into my Battery combiner box concept. I have noticed that a few places are now offering combiner boxes such as Renogy.

 

[Hedges]

Anderson connectors. If you want easy unplugging.
Most of us just bolt ring terminals. Or you can get lugs that accept a number of wires under setscrews.

I have two AGM strings on latest setup, stacked ring terminal to inverter. Fuse holder has two lugs, so will split to two inverters there. I've got a dual lug I could stack on negative terminal to do same.