So, I've seen quite a few posts now about Android System eating way more battery than it should, and I'd noticed the same thing on my phone since day 1. I tried turning features and settings on and off, disabling apps etc etc all to no avail, but I've finally cracked it
Format your external SD card via the phone settings, and use Kies to re-sync your content. Mine was originally formatted as FAT32 and I'd dragged and dropped the music and photos onto it via my computer. I don't quite understand the mechanism responsible, but this seems to be the source of my phone's unusual battery drain. Android System battery utilisation has dropped markedly, and battery life is greatly extended. I noticed the media scanner working for a few hours after I initially inserted the SD card, however after formatting and reloading via Kies the media scanner didn't run, yet all the content shows up where it should. I can only guess that some process responsible for indexing the media was running amok? Either way it's now able to sit in flight mode overnight without dropping a single %, whereas previously it'd drop at least 6%. In active use the display now always sits at the top of the battery use table rather than Android System, usually by a large margin :victory:
Format your external SD card via the phone settings, and use Kies to re-sync your content. Mine was originally formatted as FAT32 and I'd dragged and dropped the music and photos onto it via my computer. I don't quite understand the mechanism responsible, but this seems to be the source of my phone's unusual battery drain. Android System battery utilisation has dropped markedly, and battery life is greatly extended. I noticed the media scanner working for a few hours after I initially inserted the SD card, however after formatting and reloading via Kies the media scanner didn't run, yet all the content shows up where it should. I can only guess that some process responsible for indexing the media was running amok? Either way it's now able to sit in flight mode overnight without dropping a single %, whereas previously it'd drop at least 6%. In active use the display now always sits at the top of the battery use table rather than Android System, usually by a large margin :victory: