Not only are you helping the battery, but prefetching a lot of data, is also a good way to structure your app. It leads to better User Experience in the app if implemented correctly. If you start relying less on On-Demand connections in your app, you can separate UI code and Network code much more easily, which speeds up the UI and enables/improves offline functionality. Doing it in an IntentService on Android also allows for implementing very specific scheduling strategy.