It’s possible to fast charge your iPhone using a Lightning cable, but only under specific circumstances. You need an iPhone 8 or later, a USB-C to Lightning cable, and a USB-C power adapter from Apple that supports at least 18W. But that’s not all. You’ll need a 20W power adapter from Apple if you want to fast charge your iPhone 12 or later. You can also fast charge your iPhone 8 or newer using a third-party USB-C adapter that supports USB Power Delivery (USB-PD). You can check the wattage of your Apple adapter by looking at the top or bottom of the adapter.