Am currently using iPhone 13 on ios17 still planning to update iOS18 with battery health of 88 for past 3 years, is it worth to upgrade to iPhone 15 pro max because battery is not holding up for a day also and have minor lag and slowing while using the phone or to continue with this phone by changing battery or to wait for next year
hi bro, if previous 13 model was suitable for your usage, update to iOS 18 and see how it works for 1 week bro. if issue continues, then take backup and perform iOS Restore once. then restore your backup.
If iOS being the reason for battery drain, this will help fixing it.
Otherwise you many proceed wiht the upgrade bro. that will help.