'Andriod System' high battery usage - HTC Legend

[HSV Guy]

For some reason when I enable WiFi or mobile data on my phone (and then turn it off or leave it on) the 'Andriod System' process keeps the phone awake and hammers the CPU (see below picture). This results in the battery only lasting a few hours. The phone is a HTC Legend (601) and my wife has the same phone without any issues. I have gone through various options and can't see anything that would be causing this.

The only way to fix it seems to be to restart the phone. I've tried turning WiFi/mobile data back on and off and putting the phone into Airport Mode but it doesn't seem to do anything. The screen shot on the left is from the 'Battery Doctor' app and the one of the right is from the built in HTC Power app. As long as 'Android System' isn't hammer the CPU the battery last a normal amount of time (2ish days).

 

[B. Diddy]

Welcome to Android Central! This is going to sound silly, but if you have an alarm set, try turning it off. I've seen some reports of crazy awake times that seem to be associated the alarm clock. It's almost like the phone keeps itself awake so as not to forget to trigger the alarm.

 

[HSV Guy]

This is going to sound silly, but if you have an alarm set, try turning it off.

That sounds more than silly.... but it has actually seemed to work!

That's probably the last thing I would have thought of though. No idea why it suddenly started to become an issue though. Only think I can think of is that it started around the same time as when I upgraded Android to KitKat (but can't be sure). I'll experiment this week with regards to how to make it go away once it starts without rebooting the phone.

 

[Rukbat]

Welcome to Android Central! This is going to sound silly

It's not silly, really. There are two ways for an alarm to work. The right way is to make an entry into crontab for the alarm time. Linux keeps track of that as part of its normal operation, and when the time and date of a crontab entry comes along, the event is triggered. The other way is to have the alarm app check the time every second or every minute. That keeps the phone awake. Methinks someone tabbed the cron on the update. (This is a family forum, right? I can't mention a pooch?)