Why does my battery discharge so fast?

Aside from a faulty battery, software updates can also trigger your device to drain battery quickly.

There are three methods you can try out:

1. Quit background apps then restart phone.
2. Wipe cache partition on your Galaxy Note 8.
3. Master reset/Factory data reset.

It is also recommended to monitor your battery usage regularly. By monitoring means viewing the estimated battery life based on how much you have used over the past week and likewise determining how much battery your apps are consuming.

Aside from managing battery usage for each app, there are some tips that can also help preserve battery life on your Galaxy Note 8.

Including:

Enable auto-brightness

Adjust screen timeout

Block accidental touches

Use Power Saving Mode

If your Samsung Galaxy Note 8 battery is still draining so quickly after applying all prior workarounds and battery-saving tips, then you should consider escalating the problem to Samsung Support for further recommendations.