Battery life decreased after installing iOS 6.1.4

I recently updated the software of my iPhone 5 to iOS 6.1.4. I did not actually find any difference in the new update, so i guess it's related to the background processes; however, eversince the upgrade, the battery life on my phone decreased dramatically.

Currently, on minimum Phone, SMS, & Email basic usage (3 to 4 times), the battery lasts (in best cases) for 5 hours.

I have tried to reset the phone settings one by one, and again full phone reset, tried to backup & restore the phone; however, nothing worked.

The phone is less than 5 months old, and I am very organised in recharching, as I always recharge it before it reaches 20% of the battery (that was before the software update, as now the phone gets to shut down alot), never overcharged the phone, and I only use the cable and charger provided with the phone at the time of purchase (I do not thing the cable would live long as i use it at home, in car, at the office, and during social visits).

Please help.