I’m so use to my iPhone’s battery losing charge quick that I keep my Switch in Airplane mode, screen dimmed to %50 and the volume somewhat low when not on the charger
I haven't had issues yet I left mine 100% for four days in the carry case and was at 80% when I went to play it lol and my battery life while constantly playing botw is a good five hours
my original switch started to die in handheld mode quickly after only 1-2 hours max, i had to send my switch to nintendo and they replaced it as it was faulty