I have the exact same issue - 255% showing, battery not powering the laptop (Asus Rog Strix GL702Z), the device completly shutting down when the power cable is removed, also have the issue of the processor not working to full capacity as it was befor the May update. I have changed the power cables and the battery, at great expense, and the issue is still evident. I have also taken it in to an IT repair shop who advised it was a hardware issue...another £100, needless to say I wont be using them again!
I have uninstalled the battery drivers, reinstalled them, restarted the machine with and without the battery installed - having tried two batteries and power supplies - and I still have the issue. I have also done all of this with the most recent MS Update (2004) - what next?
Has anyone found a simple fix for this - we are not all confident computer specialists!
Thanks.