After Updating the iOS 7.04 on my iPhone 4s drain battery quickly on standby mode & also doesn't respond volume up button, why?

Question

After Updating the iOS 7.04 on my iPhone 4S drain battery quickly even on standby mode & also doesn't respond volume up button, why?

Answer 1

My battery problem woes continues to persist.  Yesterday, I had about 85-90% battery life in the morning.  A couple hours later when I looked at the phone it was down to 65%.  At that point, I shut off wi-fi, bluetooth, and background app refresh.  I received one call shortly after that.  The call lasted about two minutes.  My battery was now down to 40%.  Another hour later, down to 16%!  Here's the kicker:  I plugged in the phone to a charger and it jumped to 65% in a matter of minutes.  I unplugged the phone and within a couple of hours it was back down to around 30%.  I plugged it in again and within 10 minutes it was up to 75%.
At first glance it looks very much like a hardware issue.  However, I never had this problem until I upgraded to 7.0.4.  Also, the above battery roller coaster ride isn't a constant.  That is, it seems that only sometimes this happens.  So...I'm thinking it's either an app running in the background eating up juice (though I have Background App Referesh turned off) or the iOS is buggy.