Constantly puts the device to deepsleep mode while screen off. During deepsleep mode, Wifi, 3G are turned off, background apps are stopped. Therefore, most apps are not working, including Facebook, Google Service, etc,. It then constantly wakes up in order to download email, sync Facebook status, etc,. It’s defined by deepsleep frequency and woke up duration.
http://play.google.com/store/apps/details?id=com.rootuninstaller.batrsaver
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