my iPhone turns itself off and on
my iPhone keeps turning its self of and turning back on what’s up with it
[Re-Titled by Moderator]
It sounds like your battery is failing, rather than losing capacity. Is this an original SE or a Second Edition? Use the Contact Support link at the top of this page to investigate repair options.
However, 8% is too low. You should never intentionally let it get that low, if it gets close to zero on a regular basis that will risk damaging the battery permanently. Charge it if it goes below 20%.