For the last few months just about every time I do anything on my iPhone that uses Location Services, I’ve had that icon come on and stay on. I couldn’t get it to go away unless I turned off Location Services entirely; and even then it would come right back as soon as I re-enabled it.

I know how to go into the Settings and see what servies are using Location (look for the purple arrow next to the items in the list), but every time I checked there was no active app using Location. This evening I figured it out. Turns out there is another set of services that use Location – helpfully hidden under the System Services button.

Once I finally clicked tapped through that item, I saw that Compass Calibration was actively using Location Services. Sonofa… so that’s the service that has been eating my battery for the last few months.

It’s a useful service to be sure, but for now I’ve disabled it and am enjoying being able to blissfully launch apps like Maps (then hop back out of them) without having Location Services stay active and drain my battery down to zero.