iOS software quick-fire questions

Can I use an old iPhone as an iPod?

If you just want to sync music to it from iTunes, neither a SIM card nor an Apple ID are needed. You’ll need to connect to iTunes on your Mac, as activating the device needs to be done there in the absence of a SIM card. You’ll need to sign in to an Apple ID to use other services, such as downloading new music directly to the phone.

Checking iPhone battery health

Settings > Battery > Battery Health shows the maximum charge relative to when new, and Apple’s grading of performance capability. coconutBattery for Mac (coconut-flavour.com) shows the number of charge cycles done; how many it should take for max retainable capacity to fall to 80% varies by device (see bit.ly/chgcy).