A research project by Purdue shows that a big drain of Android device batteries is the ads served by free apps. The Android app freemium model gives the app away in exchange for dishing out ads in the app. This is often done by checking the device GPS to determine the phone location, to serve ads pertinent to the user's location. Unfortunately, The Purdue research shows the battery drain of the ads is up to three times the drain of running the actual app.
Android device owners, phones owners in particular, know that it's a constant battle to tweak the settings to make the battery last as long as possible. Since the freemium model is commonly used in Android apps, this constant drain caused by app ads may be the culprit.
It's shocking that this research determined that only 10 - 30 percent of the battery used by popular free apps is from actually running the app. The lion's share of the drain is all due to the ads being served while running the app. That's not a very good tradeoff to avoid paying a buck or two for an app.
If there is a paid version of your favorite apps it may be a good idea to bite the bullet and pay up. Turning off these power-hungry ads can only be a good thing, and maybe your phone battery will start lasting as long as it should.