According to a recent study, free apps will drain your battery faster than those you paid for. Researchers at Purdue University found that free apps, which usually fill part of your screen with ads, use a lot of energy loading those ads. From the BBC: “Findings suggested that in one case 75% of an app’s energy consumption was spent on powering advertisements.”

The study shows that a good portion of your battery life is eaten up by apps that are trying to send ads based on your location. Those apps automatically update and link to a GPS satellite even when you’re not angry birding. Here’s a tip: if you’re not using all those apps you have open on your smartphone (especially those location based apps that keep updating in the background), you should turn them off.