Anyone replaced the battery?

Has anyone replaced the battery on the 945? Curious if it made much improvement?

My watch is over 5 years old. I feel like I'm charging it more often, every few days. Pulse Ox is off as I'm aware that's a drain.

So wondering about changing the battery. At 5 years, I'd be surprised if it isn't degraded.

And presumably replacement batteries have come a long way in 5 years. Some are advertising way higher mAH values, although appreciate with copies this could be garbage.

Interestingly, I just charged to 100%, and ran a GPS walk test off my wrist. Did 7 hours with 67% remaining, which actually seems pretty good. So maybe it's software rather than physical battery degredation. 

Any thoughts?