Sudden drastic battery drain

[Deleted User]

Hi,

I bought the HTC One M9 a few months ago. Everything worked fine until yesterday. It was at 100%, I was on whatsapp sending a message and suddenly it switched off and the battery picture showed that it was at 0%.

I tried to charge it and it stayed at 0% for a while. After an hour so, it finally switched back on and I kept it charging overnight. This morning it was at 100%, within 2 hours, it went down to 20%. A few minutes later, 7%. I charged it again but it is slow to charge.

I haven't really been using the phone as I'm at work so I have no idea what's going on. I haven't installed any new apps. I just upgraded to the latest HTC system update for the phone today but it doesn't seem to help.

Within typing this message, it's gone from 24% to 19% and I already have battery saver mode on.

I'm on the EE network (UK). The phone is not rooted.

Any idea what's going on?

Thanks a lot

 

[SolApathy]

If you have not done any app updates aside from the HTC update, something may be awry in the kernel. You can check the battery stats to see what is causing the drain, perform hard restart and flush the cache. Worst case you may need to complete a factory reset.

You can download a battery monitoring app like GSam to see if an app is malfunctioning first.

Hard restart:

Press and hold both Power+Volume Up button together for around 10 seconds and a message will pop up advising you to continue holding the buttons to force the restart.

Flushing cache:

1. Ensure the device is powered off.
2. Press and hold the Volume Down button (middle button located on the right edge) then press and hold the Power button (located on the right edge; first button from the bottom).
3. Once HTC logo appears on-screen, release all buttons.
4. Select reboot to bootloader.
   
   
   Utilize the Volume buttons to highlight and the Power button to select.
   
   
   Allow approximately 10 seconds for device to reboot.
5. Select BOOT TO RECOVERY MODE.
   
   
   Allow approximately 10 seconds for device to reboot.
6. Select wipe cache partition.
7. Select reboot system now.
   
   
   The device may take up to 60 seconds to restart.

Hard (**FACTORY RESET**)

This is a last resort, but sometimes it is needed after a system update doesn't go quite right.

1. Go to Settings, and then tap Backup & reset.
2. Tap Reset phone.
3. Tap OK.

 

[Deleted User]

Thanks a lot for your reply and suggestions.

I tried them (including the factory reset...) and the draining isn't as bad but definitely worse than before it suddenly gave up on Sunday. I'm going to have to send it in to be looked at.

Thanks again though and I'm saving your suggestions for the future.