LFP Balancing

[senormechanico]

I purchased a NEEY 4th generation active smart balancer for my home's 8 cell, 700 aH system. I thought they were pretty closely balanced, but found out about half of them were nearly 100 millivolts lower than the highest cell.
It took about five days for the NEEY to get them perfectly balanced running only on solar, but they now are staying between 0.002 and 0.010 volts depending on how much load they are providing. Our hot water tank is the main user, set for heat pump operation and 120 degrees f.


I like how it performs, so I purchased a second NEEY for the boat and just an hour ago, got it hooked up.
4 cells, 200 aH.

[sv_isara]

I worked for a battery company testing and recovering 1000s of LiFe batteries. I'm not the best expert with marine systems, but I can say that life batteries with large loads from cold and from a depleted SOC can totally wreck end cells and cause battery bms's to constantly be in a state of catch up, and it can certainly end with bulged cells and cell balance SOC that's way wacky, like 2.4v and 4v, and a dying or dead battery.
End cells fail most commonly in the failure mode described above, but middle cells can fail as well, just less commonly.

So to answer the OP's question directly, yes ot can matter.But it shouldn't with most batteries that have been kept up well.

Even with good batteries though, some naturally balance much better than others. Good idea to confirm the bms balancing voltage triggers to make sure you leave them balancing semi regularly. Weekly for a daily cycle seems like a good practical timeframe. Check for bulging (probably can't with most marine batteries anyway), and overall performance etc and that's all you can do.

Gonna be dropping a 600Ah system in myself soon