Apple Watch 7, charging & battery life

my watch 7 with fast charger does not seem to be charging as fast as it used to. It is now taking about an 1.5 hour when it used to be less, and also seems to barely make it through a day and hold full charge.

my use has not changed and for past year 1/2 have only been charging while I showered. Was always able to track my sleep and several days in a row it died during the night. Started to pay closer attention because I was not getting a low batter warning before bed. Even when Inhad 30% battery before bed, I would wake up with 5% or less. Also noticed when I started charge with 12% at an 1 1/2 hr I was still only at 96%.

tried full shut down, and update, still only marginally better.

can the charger loose it’s effectiveness?