Apple Watch Series 5 Battery Draining Faster Than Normal

I have the apple watch series 5, which I got for my birthday last year. It’s been a little over a year now and i’ve no issues with it. I’ve noticed that my battery has been draining faster than normal. normally I can sleep with it on every other night and charge it the next day. Especially when I work, I start at 100% and by the time I get home it’s already at 30%. I try to close all my apps when not in use as much as possible. Before it used to start at 100%, and at the least get to maybe 70%. Now I have to charge it every night.

Of course my iphone has to updated before I can update it but I’m very wary of updating to ios 15 as I have older iphone (iphone xr) and as far as I know you cannot update the watch without updating the phone. I just recently updated to ios 14.8.1 for those who haven’t updated to ios 15, but still cannot update my apple watch to latest software. I hoping that if i update my watch, it could help with making my battery last longer throughout the day. Does anyone have this issue or is it just me. it could be just me having a slightly older apple watch. idk 🤷🏽‍♀️