Battery Wiring/Configuration

[Frayed Knot]

I’m currently (!) in the planning phase of installing a new Lithium battery bank. There will be either three or four batteries (depending what I can best fit into the available space) in parallel. I am now wondering if, instead of the usual “daisy chain” + - + and - to - links it would be ok to connect all to centrally positioned, common pos and neg bus bars, which would then allow neat connection points for the various take-offs etc.

 

[PaulRainbow]

Busbar connections are preferable with Lithium. But what exactly is it you are fitting? Link to them ?

 

[VicS]

I’m currently (!) in the planning phase of installing a new Lithium battery bank. There will be either three or four batteries (depending what I can best fit into the available space) in parallel. I am now wondering if, instead of the usual “daisy chain” + - + and - to - links it would be ok to connect all to centrally positioned, common pos and neg bus bars, which would then allow neat connection points for the various take-offs etc.

That is one way of doing it.

You might like to read SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank which describes ways of connecting multiple batteries to form one bank without introducing uneven voltage drops .

There are many other useful items to read on the "technical Info" tab on the Smartgauge website.

.

 

[PaulRainbow]

That is one way of doing it.

You might like to read SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank which describes ways of connecting multiple batteries to form one bank without introducing uneven voltage drops .

There are many other useful items to read on the "technical Info" tab on the Smartgauge website.

.

With multi battery Lithium installations it's generally considered better to connect them to busbars. Each battery having it's own fuse and isolator.

 

[Baggywrinkle]

I’m currently (!) in the planning phase of installing a new Lithium battery bank. There will be either three or four batteries (depending what I can best fit into the available space) in parallel. I am now wondering if, instead of the usual “daisy chain” + - + and - to - links it would be ok to connect all to centrally positioned, common pos and neg bus bars, which would then allow neat connection points for the various take-offs etc.

That's often exactly what you find in the Victron Schematics ...

Their schematics pages are a mine of useful information, much of which is also relevant to any system. System schematics - Victron Energy

e.g.


.... but make sure that all the positive cables to the positive bus bar are the same length, and that all the negative cables to the negative bus bar are the same length. Every battery needs to see the same voltage drop in the cables or each battery will be at a slightly different voltage. It's what I'm going to do with my Lithium install too.

 

[PaulRainbow]

That's often exactly what you find in the Victron Schematics ... e.g.

View attachment 185211
.... but make sure that all the positive cables to the positive bus bar are the same length, and that all the negative cables to the negative bus bar are the same length. Every battery needs to see the same voltage drop in the cables or each battery will be at a slightly different voltage. It's what I'm going to do with my Lithium install too.

View attachment 185212

Spot on

 

[Frayed Knot]

Thanks for the advice and info (which I’ll study tonight)
Although a completely fresh/all blue installation would be ideal, as I have good quality mains charger, alternator to battery and MPPT controllers in place, all of which have lithium and/or customisable charge settings I can’t justify that expense.
I’m probably going to settle on either Fogstar or Renogy batteries. I’m tempted by a single Fogstar 460 which would fit the space perfectly but there’s the “eggs & basket” consideration.
As to what I’m linking Paul, I was really just talking about the outlet to the distribution board, common neg. plus the charge cables & monitor.
I was unaware of the cable lengths issue so extra thanks for that, which also means a bus bar makes a lot more sense.
Having come up with an idea which is actually the correct way to do it, I’m not sure if that means I’m cleverer than I thought I was, or something less comforting.

 

[Frayed Knot]

“Fogstar or Renogy”
Unless anyone has alternative suggestions in a similar quality and price band.

 

[Frayed Knot]

That is one way of doing it.

You might like to read SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank which describes ways of connecting multiple batteries to form one bank without introducing uneven voltage drops .

There are many other useful items to read on the "technical Info" tab on the Smartgauge website.

.

That’s really helpful, thanks for that. Those figures are stunning, difficult to believe.

 

[PaulRainbow]

That’s really helpful, thanks for that. Those figures are stunning, difficult to believe.

Method 3 is the one best suited to Lithium installations, with each battery being individually fused and switched. The comments about cable lengths are doubly important with Lithium.