[Q] Battery percentage doesn't drop normally. topic

C6903 4.4.4 157 rooted.
It reaches 90% dropping normally and the sudden drop 81% and then another sudent drop to 76% ... ect. The drop is not a regular number.
I had the issu on 108 and now same with 157. 2h SOT and it's still 72% i hop that's true, but need help.

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