Help Sudden shutdowns and battery loss

[Askr]

Hey there,

it just happened again that I woke up, wondering why it's so late and then realize my phone blacked out again at some point this night, leaving me without alarm. I didn't figure out what causes this problem yet, so that's why I'm looking for help here. Here are two screenshots of the built-in battery app:
http://i.imgur.com/HI6mf.png
http://i.imgur.com/pC9R1.png
As you can see at some point the battery just DROPS from mostly full to almost empty. In the same process (I think at least) the phone shuts down. The last thing I did to the phone was to update to ICS a week before, but I think I had these troubles before as well.

I'm using Juice Defender Pro in case you're wondering why connectivity is disabled every 15 minutes.

 

[Calvo1]

I had this exact same problem. I thought my battery was at fault so i tried a new one and it still happened.

Im pretty sure that it is the ICS update you have installed.

Im not going to say i know for definite but what i do know is that i updated my ICS to the Andy X Rom and i havent had a problem since. it has been excellent so far.

 

[IRULE010]

I'm suffering from the same problem. If anyone can find a fix I'd love to hear it.

What's the best custom rom?