The real story behind MagSafe, USB-C PD, and why you need a 20W AC charger | AppleInsider

If you want to charge your iPhone 12 using MagSafe, Apple recommends using certain 20W AC adapters — and they don't need to come from Apple, despite what you may have heard. We explain what the requirements are, and why an older 18W adapter just won't cut it.
Read more: https://appleinsider.com/articles/20/10/29/the-real-story-behind-magsafe-usb-c-pd-and-why-you-need-a-20w-ac-charger?source=Snapzu