Battery percentage up and down

[Yudysfianda]

Hello guys

I have finder 75, I use 50watt, when battery 90% with 3-5 puff , battery is falling down to 80%,and suddenly rising slowly only add 1-2% .Where is the problem? on mod? or on the battery? or escribe problem? please help thank you

Edited March 26, 2019 by Yudysfianda

[MacVap]

First I'd check the battery, maybe it's worn out or of not the best quality.

 

But other reasons are not excluded.