Power issue
why is my iPhone 7 Plus always shut down at 44 percent battery then show low battery and shut down. Please what can I do to resolve this because my battery life is still 100
Sounds like the battery is failed.
The only batteries at that age that still show 100% are fake replacements or failed batteries.
If it is a non Apple replacement you can’t go to Apple for another.
If its original then get a Battery Repair