Sudden severe battery drain

[MBY]

My 521 has had decent battery life up until the last few days. I've been feeling that the phone is getting very hot and finding that the battery has drained over 60% in a matter of under an hour. This has been at times with essentially no usage and almost no apps open.

The only thing I've changed recently is that I got a new BT headset (the Motorola Buds) and listening to Pandora (this part I used to do with another BT headset). The strange thing is that the precipitous battery drain never seems to occur when I'm actually listening to music or even have my phone's BT on at all.

I've tried restarting my phone, removing the battery, turning off location, and the issue persists. I downloaded the Battery Sense and Battery Doctor+ apps to try to figure out what's causing this but they're not able to specify an app that is responsible (I think 8.1 may have some native to do this, but I'm still on WP8 :-(.

Anyone have any further ideas? The phone is at least still under warranty if it turns out to be a hardware issue.

 

[Torcher Death]

I've been having battery drain ever since upgrading to cyan, so am not sure, but I think its software related problem, maybe something to do with the transparent live tiles.

 

[LockOnTech]

Same problem as above, usually it goes away after I shut the phone off and plug it on the charge again the the problem goes away on its own. Happens to me ever since I got the phone in April, it happens often but for me I am not going to stress over it. There are other issues like this in other threads on the lumia 521 section.

 

[MBY]

Through my own observation and Battery Sense's timeline, it appears this drain is happening especially *after* I finish listening to music. I've been using Pandora and Mix Radio with Bluetooth headphones. Afterwards I close the app, turn off Bluetooth and use an app to make sure the music is stopped. My battery actually drains *faster* after I stop the music than while it's on.