What cell capacity and USB Output do I need in an external charger for iPhone?
Looking for the best portable/pocket charger for iPhones 6 Plus and 8 Plus
MacBook Pro, macOS High Sierra (10.13.4), iTunes 12.7.4.76
iPhone's use a 5 volt, 1 amp , 5watt charger.
Most chargers that support iPhone's will say so on the box. Best to find ones that actually have the Made for iPhone label on them.
Also any reason you don't use the included charger?
Or do you actually mean a battery pack as opposed to a wall plug charger?
i.e: