Phone: Nokia 7 Plus
Android version: 9
Intro: My problem started few months ago when the battery life suddenly dropped. With Wifi and bluetooth turned off the phone barely lasts a day. Interestingly, turning the battery saver on makes the battery hold over two days. I investigated further: I installed Gsam Battery Monitor and after a few weeks of experimenting i can see that whenever my battery saver is not on, there is a constant CPU usage at about 20% and at 10% frequency. Without battery saver, there are still some unexplained spikes in cpu usage at weird times.
Nokia 7 Plus is rather expensive, I bought it because I wanted a dual-sim phone which would last at least a few years, but this one has barely two. I had much worse phones which lasted 2x times that.
I tried deleting as many applications as I could, but this did not help, and the start of my troubles does not correspond in time to any new app installation, so if anything, I suspect google screwed something in an update.
The question: What can I do to troubleshoot this? Is there a way to find out what keeps the CPU running and spiking at weird hours?