I've been slowly becoming aware that Google Maps is eating up a lot of the power on my phone (an HTC One X with Android 4.1). Yesterday as my battery was near death I saw it was up to 25% of total usage on a day when I hadn't even run the app. Something had to give. I'd already turned off Google Latitude a few months ago so the culprit had to be whatever secret-squirrel location sniffing the phone does behind my back.
Android has about a million different incomprehensible weasily location options. At least in 4.1, I've seen some evidence that 4.2 is a bit better. The bargain with 'Google's location service' seems to be that if you don't send your data to them they won't send it to you. At least I think so, the description changes when you check or uncheck the option. I've had this off for today and my battery has a lot more juice. It means that Google Now doesn't work, but so far that doesn't seem to be a loss. It might hurt other apps as well, but so far I care more about not having a dead phone at the end of the day.