I actually found this after googling exactly that issue. I have an iPhone 12 Pro, the transparent acrylic case made by Apple (that has the ring on the back), the MagSafe puck and the 20W brick/plug from Apple. And *every single time* I charge it using the puck it gets *very* hot. Not enough to actually burn my hand, but enough that it doesn’t feel right, and I cant imagine that regular heat not affecting the electronics in the device.
I‘ve been using an iQ charger since my iPhone X, and never had an issue with wireless charging. Same thing with this phone, it has no issues with other iQ chargers (I own three besides the Apple MagSafe puck.) but they’re, of course, much slower.
I wonder if mine is defective. I must say I’m *very* disappointed with this issue. Apple charges us $20 for the brick (and wants applause for that. I’m sorry the research they quoted for the decision was for old bricks, which haven’t changed in years. The iPhone 12 is the first to use a 20W charger brick, so anyone aware of that *would* use it. So the trees still got cut Apple, you’re just charging more it.) plus $40 for the puck. Plus $50 for the case. I paid that so I could enjoy the *premium* charging experience of their flagship iPhone. And what I get is a phone and puck that are both extremely hot.
I apologize for the rant. I now never charge with the puck with the screen facing up, because if the puck is between the phone and another surface, the heat is even worse! So I only use it with the phone facing down, and the puck on top. And as I said both the phone *and* puck get extremely hot. I also haven‘t noticed any difference in temperature based on the battery charge level. To me it always stays hot until I pull the phone away from the puck. Then the temperature goes down very fast.
If this is happening during winter, I can’t imagine the disaster it could be when it’s summertime...
