Battery drains very fast on 4S after upgrading to iOS 6

My phone battery was performing reasonably fine before the iOS 6. Now:

• The battery gets drained very fast. It used to last for 24hrs (on average) on the previous OS but now does not work for than 14hrs.
• The phone gets switched off when the battery reaches 10%. So basically I am only using 90% of my battery

If Apple is not going to fix this issue then i have no solution except to downgrade it to iOS 5.1.1

Any suggestion or advice would be greatly appreciated.

Thanks