Issue of charging , battery drains fast and sound calling

[Arijit]

My device Max pro m2 new charging issue slow charge and battery drains fast after last security update i noticed and old problem sound when calling too low without use loud speaker very critical to talk on android 9. Please help

[victor010]

Please follow below steps may improve battery backup:
1. Enable “Power saver” (Settings > Power management)
2. Close apps that are not used (Bluetooth, WiFi, GPS, etc.)
3. Adjust sleep time and brightness (Settings > Display)
4. Boost memory when you see memory consumes is high with no app running,
5. check for background running applications, stop/disable unwanted apps, you can manage apps from auto-start manager. 

Recalibrate battery
To recalibrate battery, charge your phone to 100% without interruption.
then discharge it normally till 0%(phone gets switched off).
charge it to 100% in switched off condition and keep it in that state for a little more time.
now switch on your phone in charged condition and unplug when ASUS logo appears.
keep the phone unused for 5 mins.
you will get far better battery life as the battery stats.bin file will be updated.