iOS 6.1.3 Battery Life iPhone 4S?

I have recently updated to the iOS 6.1.3 on my iPhone 4S. I've noticed the change in battery life between iOS 6.1.2 and iOS 6.1.3. My iPhone cannot last 24 hours within using it for calling, searching things on WiFi/Cellular, gaming etc. Before I have been able to successfully run Infinity Blade in iOS 6.1.2 for about 30 minutes, and the battery percentage will have only dropped 5%. Now, however, the battery percentage drops very fast. Last night, I left my iPhone on ~70% at ~10 PM and woke up at 9 AM to find that it had 17% of battery left. The phone was left locked, and all apps closed.

Is there any fix for this? Am I able to downgrade to 6.1.2? Will Apple release iOS 6.1.4 to fix this "battery drain problem"?

Thanks!

Any solutions will be much appreciated.