also please keep in mind that voltage measured during charging does not necessarily equate to the actual voltage level. If possible, suspend the charging to take a measurement.
And the "remaining" voltage also depends on the actual hysteresis cutoff point of the board. It varies by board, and probably also by temperature. I've seen values from 3.42 up to 3.51 V where the hysteresis kicked in and the output got disconnected - what you would normally call " 0 % capacity " (even though technically there's still some juice left in the battery.)
Last Edit: Feb 1, 2019 10:10:10 GMT -8 by lbendlin