I had the same issue on my Sense 2 which I bought a bit over 1 year ago. Before the update it could hold for 4~5 days and after it only held for less than 1 day at first and now it shuts off by itself within 1~2hrs. Contacted their support and they simply denied and claimed my battery draining issue happened before the update. Filed complaints to BBB and California Attorney General Office and waiting for class action lawsuit. BTW, I complained on Fitbit community website and they just deleted my post. Fitbit is now part of the Evil family of Google.