Apple's new MagSafe charger comes with some key advantages for iPhone 12 owners. Most significantly, it charges the new iPhones (all iPhone 12 models) faster than all other wireless chargers. But as MacRumors spotted, Apple just updated its support page to say that there might be are some disadvantages to the new MagSafe charger, too.
First, the MagSafe charger could leave a circular ring mark on a leather or silicone iPhone case over time. If you remember, this is not the first time Apple has been in a "ring scandal," as the HomePod notoriously leaves a white ring on some surfaces. And while this might not be a huge deal for most, it could be if you're a stickler for keeping a pristine case.
Second and more importantly, it could potentially damage the magnetic strip on your credit cards or passport if those items are placed between the iPhone and the MagSafe charger. This is most problematic for people who plan to use Apple's Leather Wallet that attaches magnetically via MagSafe. However, an easy (and necessary) solution would be to take off the Leather Wallet when charging via MagSafe because the iPhone 12 can't charge through that anyway.
Third, Apple announced that if your iPhone 12 gets too warm when charging via MagSafe, software will automatically cap charging at 80 percent. So if you find that you're iPhone isn't fully charging via MagSafe — that's why. Apple says this is to extend the lifespan of your battery."
Finally, if your iPhone is plugged into a Lightning charger and MagSafe at the same time, Apple says that it will prioritize the wired connection.