The new Traffic services on the iPhone 4s or iOS 5 is a huge battery drain. I noticed it while docked in my car that Location Services was on and Traffic was being utilized when I had no use for it. Unfortunately, at the time I wasn’t charging via the dock and saw a significant battery drain (10% drop within an hour). Turn it off if you want to conserve battery life while committing.
Head over to Settings> Location Services> System Services (very bottom) and toggle on Status Bar Icon then toggle off Traffic. While you’re at turn off Diagnostic & Usage, Location-based Ads, & Setting Time Zone.