Guys, what is the use of this ?? sometimes i can activate it, sometimes i cannot activate, how do i even get to this part 

Well, probably the overnight charging might be the culprit here. I do sometimes overnight charge. 

Yup only charge once daily when 20 to 30% balance.

I just wanna share my battery care tips

Me & my wife bought a pair of ip11 .. used from the same date

but we have different charging habit

me, the most important thing = never let the battery drops below 50%.., whenever im not using it, Ill charge it  (during driving, sleep).

my wife on the other hand, just drain until 10-20% so she start charging.

here the results after 5month.

mine still at 100% health


her

You mentioned you charge during sleep. You charge it overnight too? Thought that would be detrimental to battery health?