Apple Watch won't power up. I fixed it. Is it still Waterproof?

All reset efforts don’t work. Gets hot on the magnetic charger. Every once in a while the apple logo appears for a few secs then fades away.

Apple wants $275 flat fee to fix it. No way.

I feel comfortable taking it apart and replacing the battery. The question is: Is the problem with the battery? What are the odds it’s the battery and not something else?

I followed the IFixit battery replacement video and successfully repaired the watch.

The old battery was significantly swollen. I was a little ticked that I found out Apple was repairing this problem in ser 2 watches, but failed to mentions that when I talked to apple support. They only wanted to charge me $270.

All the same the battery and adhesive strip were inexpensive, and after buying a Y000 tri-wing screwdriver, I successfully repaired the watch.

Here is my new question: How waterproof is the watch now? I used an adhesive strip, but it seemed so thin and flimsy I’m concerned at how waterproof the watch is now?

I saw another repair video that resealed the glass top with a B-7000” adhesive. Should I try something like that?