Adding a second Lithium Battery

[the1andonly]

I currently have one 100AH Ultramax LiFePO4 Battery. What are views on adding
1 one more of the same
2 another brand and size.
Conflicting BMS's and how to deal with them?

 

[Guigsy]

Given how flat the voltage-charge curve is, I suspect that Lithiums are probably worse than lead acid for mixing brands.

 

[Lenny HB]

Raul may know.

 

[Raul]

Adding of the same brand and size is generally practised and viewed as safe. Even victron says parallel unlimited on their super packs. Some brands restrict parallel to 4 max of the same size, some forbid parallel all together. It’s all down to the bms, and characteristics of design build.
Different size I wouldn’t, it will have different bms ratings and no communication between them.
I have 2x 200 ah in parallel, individually fused at the buss bar distribution.

 

[steveh57]

Similar to the above, I added an additional one in parallel about a month later, same brand and capacity , connected via + and -ve bus bars , equal length cables and individually fused.

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