Although the battery of my Samsung Galaxy SII lasted approximately 1 day (which I considered a success, after having battled Firefox Sync, Soundcloud and Exchange mail fetching), a couple of weeks ago I started to manually disable the data network mode at night. Who needs their phones online all of the time after all? This worked like a charm, which made me start thinking about an application that could automate toggling of the data connection. I did a quick search on the web and found this article on Stack Overflow with sample code to access the (hidden) dataconnection API’s.
While reading the comments I understood I didn’t need to find me someone to build such an application; Juice Defender does just that. The basic version is free and although it allows only limited configuration, just activating it with default settings almost doubled my SGS II’s battery life. So if you want your Android phone’s battery to last longer, you really should try out Juice Defender.