Carrier IQ

One day shortly after I started using the PRIV I decided I should try the AT&T DriveMode app. Let's just say it was aggressive. For example, I couldn't change the volume on Pocket Casts using the steering wheel controls while I was driving. I disabled it after my first drive. And then I noticed a new consumer of the battery that hadn't been present before.

Here's what the battery usage looked like before DriveMode:

Here's what the battery usage looked like after DriveMode:

Notice the battery usage by "Device Health Application" and the GPS activity.

So what is this "Device Health Application?"

This CrackBerry forum post answered that - Carrier IQ.

From my experience it seems that DriveMode triggered something in Carrier IQ that caused the GPS to run almost constantly.

A factory reset helped that but it took the Marshmallow upgrade to completely resolve this.

Here's what the battery usage looked like after Marshmallow:

Battery usage has been fine ever since and I haven't tried DriveMode again!