I have a Sony Xperia P (LT22i) phone. Sony have recently updated the software for it, so it now runs Android Jellybean. Last week, I plugged the phone into my desktop PC and the Sony software proudly announced that an upgrade was available. The existing (Ice Cream Sandwich) version had some niggly problems, so I thought upgrading was a good idea. Well, I was almost right.

The software build it installed was 6.2.A.1.100. The upgrade proceeded without a hitch, but I soon noticed a problem: the phone’s battery life had become hopelessly bad. I used to be about to use it for 24-48 hours without charging, but now it would discharge itself by more than 50% overnight without even being used. That’s useless. Looking at the power management screen, the application using most of the juice was ‘Phone’. Phone? Surely that’s the one application that they must have tested, right? It turns out I wasn’t the only one with this problem. There are forum threads about it on various sites. Look at this one:

http://talk.sonymobile.com/thread/127636?start=0&tstart=0

After much cursing and head-scratching, I managed to fix it, but the fix isn’t very nice. Basically I used the ‘repair my phone’ link in the Sony PC Companion software, which does a factory reset and reinstalls the software. It’s brutal, but effective.

The process goes like this:

• do a complete backup of the phone using the PC Companion software. Don’t be afraid of the incredibly long time it takes before it actually starts backing anything up.
• select the ‘Support Zone’, then ‘Phone/Tablet Software Update’, then use the ‘repair my phone/tablet’ link and follow the instructions.
• when your phone eventually restarts, get it connected to the internet either by Wi-fi or 3G. Add your Google account to it. Don’t try to restore the backup yet: most of it would fail because the apps aren’t installed yet.
• on a desktop PC, go to play.google.com/apps and log in with your Google account. It should show, under ‘My Apps’, a list of apps previously installed on your phone. Click on them and set them to be installed.
• the phone should now download and install the apps you’ve selected.
• when the apps are restored, restore your backup using the PC Companion software. Again, there’s a long delay before anything happens, but it works eventually. Expect a few error messages if there are any apps you had installed before but chose not to put back. They’re harmless.
• now spend ages getting everything set up the way you liked it before. Sadly the backup doesn’t keep things like your icon layout, wallpaper, notification settings, ring tones and myriad other little things.

This whole process wastes about half a day, in my experience, which is annoying. But at least my phone works properly again and doesn’t drain the battery. I just wish it hadn’t gone wrong in the first place. More testing needed, Sony, please.