Battery life with GPS navigation using Maps app

I've noticed that using the Maps app for navigation seems to eat the battery much faster than in iOS6. I had 2 trips of 15 minutes today in the car, and each of those used b/t 12% and 15% of my battery.

I was the passenger in the car during both, so on the 2nd trip I tried having the Maps app in the foreground and background, and it did not seem to change the way the battery drained. When the app was in the background, I had Tweetbot up - so I'm fairly certain it wasn't that draining the battery.

Anyone else noticing issues with the Maps app specifically?

Edit: This is on an iPhone 5 where I did an OTA upgrade.

Edit 2: During the rest of the day, the battery dropped 20% total from 9 AM to 5PM.