My battery life has plummited these last few weeks. Its not something I noticed before I got the 7.8 update. I have run the diagnostic thing and the battery output is only 3.2V and 400mah fully charged I read online that its meant to be 1000mah ! Do I need a new battery ? Id there an upgrade and why the hell does the lumia only charge with the phone on ! I'm sure this is the cause of my battery damage