[hnrodey]

I'd still replace the battery regardless of what they tell you.

Apple once told me I had a good battery even though my phone would randomly shut off and attaching to a charger was the only solution to get the phone to turn on. Thankfully I had AppleCare and pushed for them to replace the phone.

[eisa01]

Yup, download GeekBench and do a test

My iPhone 7 was had a crippled batter after one year - it performed like an iPhone 6..

[specialist]

coconutBattery now also reports the battery health of connected iOS devices. I wish this functionality was built-in.

http://www.coconut-flavour.com/coconutbattery/