I am using M3 Note and I am from India.
As per my observation, i would like to share something about M3 Note charging time and abnormal battery % increase.

First of all if you are facing long battery charging time.
Cause of this because of, when your mobile got switched off after draining battery completely and plugged into charge then if you turned ON your mobile while this it will take more than 3 hours to charge battery upto 100%. Also there will be a possibility of sudden icrease also will occur while charging. Normally our M3 Note chaging time is within 3 hours.
Solution for this is to try Battery Meter Calibration.
If you are calibrated your battery then, charge your mobile when battery is at 10%. There will be a possibility to drain fast at any % below 10%. So, charge from 10% to 100% continuously without interruption and observe your battery charging time. Also observe the battery backup when charged 100% and 10 minutes more.

These all are my personal feedbacks and opinions. Try it and tell me your resluts please.
Thanks,
Vysakh