And it's not an hour and a half either, it's 3 hours. 90 minutes of active usage.
Viewing Usage Statistics
Awareness of how you use your iPhone and knowing how long your battery typically lasts can help you improve its battery life. You can view your iPhone usage statistics by tapping the Settings icon on the Home screen and choosing General > Usage. Under the “Time since last full charge” heading you’ll see two items:
- Usage: Amount of time iPhone has been awake and in use since the last full charge. The phone is awake when you’re on a call, using email, listening to music, browsing the web, or sending and receiving text messages, or during certain background tasks such as auto-checking email.
- Standby: Amount of time iPhone has been powered on since its last full charge, including the time the phone has been asleep.
I went on facebook for 5 minutes and had google maps running because I'm routing out my trip to work by bus. No music or games. A little iMessage too.
If you had maps running then you probably had GPS going at the same time - unless you disabled it.
GPS is battery hungry and quite possible consumed that amount over 90 minutes.