I have a really strange issue with my iPhone. I had an iPhone 6 and suddenly I would notice the rear case was very warm and the battery was being discharged at an excessive rate. I have an app called System Status Pro which shows CPU usage. When the issue occurred, the CPU usage was fluctuating around 20-30%. I left it thinking iOS was busy doing stuff, but the battery continued to discharge quickly (i.e. 100% to empty in an hour or so). I force restarted the phone and everything returned to normal. CPU usage averaging 3-5% with no apps running.
This issue continued to return randomly. I could last a week with no issue, then it would happen 3 times in one day.
My investigations so far:
- The issue is not related to my phone’s hardware. I upgraded to an iPhone 8 (restoring my phone’s from a backup) and the issue continued
- The battery app in Settings, which shows each app’s CPU usage does not show a particular app causing the usage
- Background app refresh is turned off
- No obvious Apple services (i.e. iCloud backup) are running at the time of high CPU usage
- When the issue occurs CPU usage is always 20-30%. Never more, never less
- It is not iOS version specific
- The phone is not hacked/jailbroken
- The phone does not have Enterprise certificates installed (which would allow non-App Store approved apps)
- High CPU usage continues with no apps running (double clicking home button shows no apps running)
- The only resolution is to restart the phone and usually a single restart fixes it, although occasionally it returns and another restart is needed, sometimes even a third restart. But restarting always fixes it eventually
- I have 15GB free of the phone’s 64GB storage
- I realise I could wipe the phone. This is my last resort and I want to avoid this
Has anyone experienced something similar?
Does anyone know how I can view CPU usage at a more granular level, ideally identifying each individual processes CPU usage?
Many thanks in advance for any advice!