Anker PowerCore Magnetic 5K

Here's a fantastic choice for everyone who has an iPhone 12 or later. The Anker PowerCore Magnetic 5K attaches to the back of an iPhone for easy charging (earlier iPhones lack this function). The nicest thing about this power bank is that, because of its sleek and unobtrusive appearance, you can attach it to the back of your iPhone and forget it's even there. It can even charge in MagSafe-certified cases. Power banks are frequently big, so you're constantly reminded that anything is connected to your phone—not with this one.

One minor drawback is that it only charges at a sluggish 5W. However, if you purchase a USB-C to Lightning Cable (which is not included in the package), you may significantly boost the charging speed. Although it doesn't charge as quickly as some of the other units on this list, the PowerCore Magnetic 5K accomplishes the job compactly and silently, so if you don't notice the slow charge, you might be shocked that it's there at all.

Link: https://us.anker.com/products/a1619