Scooter battery conundrum

[Supervstech]

I have a hoverboard battery, it specs as 25.2V...
It has18650 cells in a 7s arrangement, making me think they are lfp cells, but the number on the cells leads me to think LiNNMC ...
Sooo...
Is the voltage wrong, or is the cell labeled wrong?

The HCYINR18650 part googles to a LiNNMC chemistry, which would be 3.7V nominal, but that pack would be 25.9V
3.6V would equal 25.2V
Maybe just a conservative charge profile?
Should I charge to 29.4V or 4.2v/cell?

 

[NVS]

18650 cells have had 3.6 or 3.7volt ratings. I don't think there is a difference in their 4.2v max charge. All the BMS you find for lithium ion charge to 4.2v. If you can control the charge voltage a lot of people say you'll get more cycles only charging to 4v.

 

[Supervstech]

Well, I charged to 29.4V, and the bms disconnected, so it must be too high.
I will try 28.7 which should be 4.1V/cell.

 

[NVS]

That's where you bms should shut off at. But it's OK to not charge cells to 4.2v.

 

[Supervstech]

Must have been a thermal disconnect, it came back on at 27.2V, so not fully charged.
I was charging at 8 amps on a 4000mAh bank, so maybe too quick a charge rate.
I'll reduce to 4A and see where it drops out.

 

[Supervstech]

3.89V per cell is too low in my opinion.