Ridiculous battery drain on LN 14.1

[nimbulan]

I installed LN 14.1 on a Nook HD+ recently, and ever since then, the battery drain has been absolutely ridiculous. It goes from fully charged to dead in 20-30 hours at idle, with 95% of the battery usage coming from LineageOS System or Android System. In troubleshooting, I've removed a bunch of apps I had installed, particularly those known to drain batteries, used Greenify on a bunch more apps, and tried some other tricks like clearing the Google Services cache and disabling location services, but it's barely helped. I eventually tried a wakelock detector, and discovered that the CPU is in high power mode 65% of the time while idle.

The battery was perfectly fine on the Nook OS. What can I do to fix this?

 

[digixmax]

Turning off WiFi while the Nook is not in use helps reducing battery drain.

 

[nimbulan]

Thanks for the tip. I actually finally traced the problem to the wifi yesterday. It seems the wifi driver prevents the CPU from going into deep sleep mode, resulting in 10x normal battery drain. I don't suppose there's any other way to fix it?

 

[ebrinkis]

Same Problem

Thanks for the tip. I actually finally traced the problem to the wifi yesterday. It seems the wifi driver prevents the CPU from going into deep sleep mode, resulting in 10x normal battery drain. I don't suppose there's any other way to fix it?

Same Problem. Anyone have any ideas? A way to change / overwrite the wifi driver? Thank you.

 

[nimbulan]

Same Problem. Anyone have any ideas? A way to change / overwrite the wifi driver? Thank you.

The only way I've found to fix it is as noted above. Open the Settings app, go to the Wi-Fi options, tap on the gear icon at the top and change "Keep Wi-Fi on during sleep" to "never". Battery drain gone!

 

[ebrinkis]

The only way I've found to fix it is as noted above. Open the Settings app, go to the Wi-Fi options, tap on the gear icon at the top and change "Keep Wi-Fi on during sleep" to "never". Battery drain gone!

Your Battery drain must be a lot less than mine. If it is on, I lose about 1% battery every minute until it dies or I turn it off. New Battery, recalibrated, tried different Lineage OS versions, same thing.

 

[nimbulan]

Your Battery drain must be a lot less than mine. If it is on, I lose about 1% battery every minute until it dies or I turn it off. New Battery, recalibrated, tried different Lineage OS versions, same thing.

It sounds like an app hogging the CPU maybe? Any information from task managers or a battery monitor?

 

[ebrinkis]

It sounds like an app hogging the CPU maybe? Any information from task managers or a battery monitor?

Nope, all wake locks, battery drain programs sit in the 1-2% area, fully acceptable. I replaced the battery, nothing changed. Not sure what to try next. Thank you very much for your suggestions though.