My iphone shuts of and then starts again
My iphone shuts down and restarts several times
iPhone SE, iOS 16
It's either a bad battery or a motherboard that is failing.
A new battery is $69 (U.S.). Unfortunately a new motherboard is a lot more.
Make an appointment at the Apple Store or take the phone to an authorized Apple service shop. You can find a list of authorized shops in your area using this link: