Ok, I know the lumia 800 had battery problems, which personally I never experienced, always got around 24 hours off a full charge. Ever since I installed windows 7.8 the battery life has decreased significantly, 10 hours if I'm lucky. Even when I fully charge the phone says it has around 12 hours remaining. All the settings are the same as before the update as to is usage. Location services, Bluetooth and data all off. Any one else with a similar problem.