Wiring a lifepo4 battery bank

[elias]

Hi,
I am planning to install a lifepo4 battery bank consisting of 3 100AH lifepo4 batteries 12v. Instead of interconnecting them with tin cable I am thinking to make a tinned bus bar from copper . The bus will be 5mm thick 25mm wide with M8 holes . There is this diagram guide I found online about cabling lead acid batteries but does this apply to lithium ? Do they have internal resistance behaviour like that?
I am planning to put parallel the bus bars passing and connecting the positive and negative poles of the batteries .

[Baddox]

Putting aside the inability to balance the batteries independently if they are connected by a bus bar. I expect that fastening them together with an inflexible bar may cause fatigue and damage as the move even very slightly.  A well made cable and lug should be al you need without any of the disadvantages of a rigid bar.

[elias]

Hmm I m not aware that I have to balance them regularly , I think BMS does that and I can do it very 6 months (the boat sails 6months per year) with the victron charger , or not?

In all the previous banks I ve installed I screw down to the floor the batteries with some distance between them . As I am planning to do now but with an extra frame around them . My guess is since they are fixed the bar is not gonna stress them , since there aren’t any forces applied to the bar except the cables elasticity coming from loads/charges. Is true that if the bar was the only element keeping them fixed it could be a problem. Maybe are you talking for some other stress force like vibration?

[JEN-et-ROSS]

if they are connected by a bus bar. I expect that fastening them together with an inflexible bar may cause fatigue and damage as the move even very slightly.  A well made cable and lug should be al you need without any of the disadvantages of a rigid bar.

I can envisage this as a potential problem as the battery terminals are only supported by the plastic casing as they pass through to connect with whatever magic happens inside these batteries..
Everything moves, flexes in a seaway, so a rigid busbar may be an unknown risk to your new very expensive battery bank...
 I've seen rigid copper bar used as heavy duty connections, but they all have 'corrugations' to allow for heat expansion and permit flexing..

[elias]

By corrugations you mean the U shape in some connectors . Aha that’s why they have it , I just read a paper from a researcher on introducing the U shape bent so it reduces expansion and stress.
Thanks a lot for your advices . I reconsider and come back .

[Ailatan]

I am going to use these cables. They are quite flexible beside their size
https://a.aliexpress.com/_EzaXl9f

[IslandAlchemy]

It is also recommended that you have a separate fuse for each battery, to protect them. You cannot do this with a busbar. You should ideally have a separate positive cable for each battery, with a fuse in it.

[Impavidus]

See the extract from the Victron wiring guide. Bus Bars are best but cables of equal length are required to ensure that the charge and discharge is equal across all the batteries. See the attached diagram. Your BMS should contain and active battery cell balancer. When the individual cells reach around 3.55v the balancer will level the charge state of each cell. This can be above the 3.7v nominal charge up to 4.2v The rate (in amps) at which this happens differs with the BMS.
Hope this helps