Ok. I've realised something happening to the display settings on my phone, namely the screen timeout and brightness settings. When ever my phone goes into 'power saving mode' on a low battery, mines set to 10% threshold, the auto brightness setting turns off and my screen timeout reverts to the lowest setting. I then have to switch the auto brightness back on and set my timeout back to 30 seconds. Under power saving I set my screen brightness, and timeout, to the lowest value and it's these settings that stay even when my battery goes above 10%. I though my own settings would be restored above the 10% threshold?