Apple Watch Beta 8 battery draining

I upgraded to Apple Watch 8 and IOS 15 two days ago, yesterday afternoon my iPhone's screen began to go black on a random basis. I seemed that to tap it would restore it. Then My Apple Watch began warming up and draining the battery at a rapid rate , it went to 7% power from 87% in less than three hours. When I put it on the charger it didn't seem to take a charge, it took over 4 hours to get it back up to 67% . My concern is , when ( hopefully **** soon ) a new beta upgrade comes out my watch will not be able to achieve the required 50% power level for the upgrade to take place