Same problem suddenly today. I was at 85% when I left the house this morning. 9 hours later, I am at 23%. I have not used the GPS and have barely walked away from my desk today
Problem is probably related with Bluetooth. I noticed that the bt-icon is constantly displayed even if disconnected by distance. Before update this icon was only shown in case of active connection between watch and smartphone.
Go to the Garmin warranty/repair page and enter your serial number. Mine was past the 12-month warranty period but they still told me that my device qualified for a warranty replacement/repair. They sent a pre-paid label by e-mail and I have sent my device back...awaiting the replacement.
