Smartphones are known for zapping their battery power pretty quickly . However, most handsets, including Apple's iPhone, offer a battery usage option that displays which services or functions of the phone are using the most battery life. Here's how to view your battery usage statistics.
From the Home Screen select Settings
Chose General and then select Usage
You'll be able to see what percentage of time 'since the last full charge' that the handset has been in use or has been on standby. You'll be able to adjust your settings accordingly to improve the battery usage time.