Given SLaSZT already gave an answer in
https://kbin.social/m/games@sh.itjust.works/t/202790/Gaming-handhelds-like-the-Switch-and-Steam-Deck-will-need#entry-comment-836808
Which isn’t far from this post
I don’t think you asked this in good faith.
A battery that can be popped out and replaced, with no tools and no risk of damaging any of the other hardware on the board.
Just supplying the tools and steps is absolutely not enough. We’re talking about replacing a part on a $300+ machine. Most people would be scared to do that purely on the merits they couldn’t afford to replace if something went wrong.