How long for change my battery

Depending on your device and charger, most iPhones with the standard 5w charge can take from 2-3 hours to full charge from 0% that gets faster with the 12w charger and with the iPhone 8 onwards the fast charging 29w+ can lower those times to just under 1 hour.

Apologies I misread the question, if you’re talking your device to an Apple store it wouldn’t normally take more than 30 minuets but that depends on how busy the store is.