HTC Droid Eris :: Google Navigator - Battery Usage Tip

I did some testing with the Navigator yesterday and I have to say it's absolutely awesome. I'm not sure if anyone has posted this, couldn't find any mention of it, but I want to share my battery usage experience with it as well as some other cool things I noticed.

Very cool battery saver:
I used it for a 15-minute drive, keeping it only in the Notification Bar. When you are in the Navigation app, you can press the Home softkey to go back to your home screen. This keeps Navigator working in the background, but it is not drawing the maps and using the screen. You can press the Power button to put your phone to sleep, and the voice actually still talks to you and tells you when to turn. And even better, I started this trip with 76% battery and ended with 76% battery.

Now, the not-so-cool.
I used it for a 30-minute drive, keeping the screen on and letting it show me the map the entire way. I started the drive with 54% battery ended with 34% battery. So definitely keep it on the charger if you are using it for a long drive. But another awesome thing I noticed. I made a phone call toward the end of my destination, just to see what would happen. I used the Home key to back out of the Navigator (but keeping it in the background, as I said above), then made my call as normal. The Navigator still gave me directions while I was on the phone. It came through the earpiece now, so the other person doesn't hear it. How freaking cool is that?