Apple

Probably cold and old. Id recalibrate the battery by taking it from 0 to 100 to 0 multiple times.

Probably needs a new battery if it’s never been replaced. That 94% health is most likely inaccurate

Definitely replace the battery. That battery is probably original and has been in that phone for a long time. A battery replacement will make a huge difference.

That’s one sign of a bad battery. I had it. A good replacement was the fix.

The battery is old and is needing replaced. I purchased a brand new unopened OGSE in 2022 and the battery behaved unreliably once it was down to 20% or less. I ended up replacing it at the Apple Store and it works perfectly now.

What iOS version are you running? Mine came with 16.6 and my battery would just drop all day/night with no use. I saw others mentioning that iOS 17.1 corrected their battery drain issues, so I downloaded the stock 17.1 image and installed that through finder — now my battery life is FAR better. It's night and day.

Yeah, old battery. That's what happens when the battery is bad.

My s20+ had this problem.

Back when I had the OG SE I had a battery case as it had 82% battery health. Whenever I woke up after it being charged, I would go to my campus gym from my 2 mile runs, listen to music in my wired 3.5 mm headphones, come back to my dorm and it would get down at 22% from 100%, with no charging. I would hit the button to charge it on the case, at it would be absolutely fine the rest of the day. Point is iPhones have weird battery issues often, but I wouldn't worry about it. Never phased me.

Also I have a XR now, and there was this one week where the battery was dropping like mad but then it eventually stopped doing that, and now I have a Mophie juice access pack on it just in case (I'm pissed Mophie gave up on those btw because they had the best design for battery cases)