My first reply at this forum..
If you select 0mV, your CM message Zero peak.
But If you select 15mV, I think that CM tell you Peak cut.
When you chrage by using CTX mode,
working Long-lock-out till the second step(2/3).
Long-lock-out means no stop(cut off) by peak detecting.
When start the third step,
CM detects your batteries` delta peak that you set up.
I think, you set zero peak(0mV),
or you stored 15mV at peak charge mode.
Each charge mode has each set-ups.
If you use 0V discharger likes Zero-v discharger by Muchmore,
You have to set Long-lock-out
about 20minutes in peak charge mode
When you push the start button in peak charge mode,
you push the button during 3 seconds!
Then your CM display Key-icon instead of 15mV.
Key icon means Long-lock-out is functioning.
I hope my coach ryan tell you more things about Cell Master.
Cell Master is my best weapon in race
Sorry for my poor english..