LiFePO4 termination currents

[Burgerman]

These should be OK as a good starting point.

2.3333mA termination per Ah. Typical for many LiFePO4 cells.
Set a MANUAL termination current.
This is APPROX and may need fine tuning as all cells are a little different.
Aim for around 30 minutes at CV after balance ends at 3.600V per cell in a normal daily charge.

5Ah = 12mA
10Ah = 23mA
20Ah = 46mA
30Ah = 70mA
40Ah = 94mA
50Ah = 116mA
60Ah = 140mA
70Ah = 163mA
80Ah = 187mA
90Ah = 210mA
100Ah = 232mA
120Ah = 280mA
140Ah = 327mA
180Ah = 420mA
200Ah = 464mA

Ah x 2.333 gives the mA termination current and these figures.

So a 230Ah pack would be 230 x 2.33333 recurring in mA. Or 536mA termination point for a 30min CV.

How do these line up with your experiences?
Longer than 30 mins is not great for the cells. Less than 30 mins leaves the last cell to reach its 3.600V during balance slightly under charged and not fully balanced. This takes a 30 min soak time to achieve.

[shirley_hkg]

What if charged @3.55V ?

[Burgerman]

It will be SLIGHTLY less current at termination. The idea is that you get it so the cells are all balanced + 20 to 40 mins at the high voktage and then let the cells relax. The figures above might not en do that its just a start point thaseems to work pretty well.

Old cells may need a higher setting and the very best cells should need a little less. Also deeply discharged ones ight need more than 30 mins if they are charged at a higher rate. And if charged slowly then 15 mins at top voltage after balance ends may be enough.

And high C rate or low impedance cells usually need less CV time too. And the opposite is also true. You probably already know this stuff though