One additional thought - while 8900s seem to have efficient radios - you can (and I do) leave WiFi and Bluetooth turned on all the time - even when I am not near any WiFi hotspot - one thing that will kill the battery on an 8900 is GPS. Any app that tries to automatically or periodically get a GPS location under circumstances where it's not possible (like you're indoors most of the time) will run the battery down in short order.