High processor/CPU load on iPhone, draining battery, how to fix?
My iPhone sometimes gets very hot and drains battery extremely quickly. When I use the app iStat to check processor load, it shows high numbers (above 2, where it is normally 0.5, not sure about the format of those numbers but that is what is reported). It seem to be the equivalent of a computer stuck at 100% CPU load.
Restarting the iPhone and closing all apps does not help. Previously, it went away after a number of restarts, but this time, so far not. Do you know a way, except re-installing, that can fix the iPhone? Any app that can kill all processes?
I had exactly this problem on my a little over one year old iPhone 4. The battery was draining in like 4 hours and the CPU was working overtime all the time.
All i did was a backup and then a restore in iTunes. It worked perfectly. The battery drained less than a percent in the following four hours!
I'm trying to figure out if it was any particular app that was causing the problem by uninstalling some of the later ones.
Do you use Exchange on your iPhone? At our company we have some trouble with contact sync every once in a while. Various iPhones will run at 80% CPU and their batteries empty in about 2 hours.
One temporary fix is to turn off contacts in Exchange Settings and turn it on again. Then contacts will be sync again and after this CPU runs at a normal 5-15%.
iPhone 3GS, iPad(3G 3rd generation), & iPod Touch(4G 4th generation) were all getting terrible battery life after iOS 6 update.
Solution for me was to turn off Push for email and other network features. This brought battery life back to where it was before the iOS6 upgrade:
- Go to Settings > Mail, Contacts, and Calendars > Fetch New Data
- Disable push e-mail and set "Fetch" to manual."
Taken from this article with other good tips as well but for me the key was turning off Push as this essentially seems to keep the phone active and connected constantly.
A great app (free) from the engineering department at UC Berkeley has been released specifically for debugging problems such as this. It's available through the app store so does not require jailbreaking. The method involves running the app for several days to a week. During that time it logs the energy usage of the various apps that you are running. You can then see which are the energy hogs that are causing the problem.
http://carat.cs.berkeley.edu