It's normal for an iPhone to get slightly warm when charging. The battery is working, the charge controller is pushing current, and the processor isn't idle. But when the phone gets so hot that it hurts to hold, the screen starts to dim, or a system overheat warning appears—that's a completely different story.
Common reasons for overheating during charging
Cheap cable or uncertified charger
The most cliché yet most common story. Someone brings in an iPhone 13—it gets terribly hot, reaching an uncomfortable temperature in half an hour. We ask, "What are you charging it with?" Turns out, they bought a cable on a marketplace for двести рублей. We swapped it out, plugged in a proper MFi-certified one—and the problem disappeared. Cheap cables don't maintain a stable current, which puts the charge controller under constant stress, causing it to heat up along with the entire phone.
Background processes and iOS updates
If you put your phone on charge right after an iOS update or during active iCloud synchronization, it will get hot. At this moment, the processor is fully loaded: reindexing photos, double-checking settings, and finishing component installations. This usually resolves on its own in 15–20 minutes. There's no point in bringing a phone to a service center just because it got warm once after an update.
Wireless charging
MagSafe and Qi always generate more heat than a cable. It's physics: some energy is lost as heat during induction transfer. On iPhone 12 and newer with MagSafe 15 Вт, the body can heat up to 40–42 degrees—this is acceptable, but noticeable. If you put your phone on a wireless charger in a case, take it off. The case traps heat, and the temperature rises.
Old or degraded battery
A battery with a capacity below 80% struggles to charge. Internal resistance has increased, current flows through it, and heat is generated. We had a case: someone brought in an iPhone X that worked fine overall, but got so hot during charging that it left heat marks on the table. We checked the battery—it was at 61%. After replacement, everything went back to normal. You can check the capacity right on your phone: Settings → Battery → Battery Health.
Debris or deformation in the port
Dust, pocket lint, or deformed contacts in the Lightning or USB-C port cause an unstable connection. The charge controller struggles, and the phone heats up while charging slowly at the same time. This is visible to the naked eye: the cable doesn't go all the way in or wobbles. Sometimes, cleaning the port with a dry toothbrush for five minutes solves the problem.
What you can do yourself
- Switch to an original Apple cable and charger or ones marked MFi.
- Remove the case while charging—this is especially true for thick leather and silicone ones.
- Check Settings → Battery → Battery Health. Less than 80% means the battery needs to be replaced.
- Do not leave your phone to charge under a pillow, in a closed drawer, or in direct sunlight—this forces overheating.
- Give your phone 20 minutes after an update. If it just updated and got warm, everything will settle down on its own.
When you can't handle it yourself anymore
There are symptoms where you shouldn't delay:
- The phone gets very hot even with the screen off and not charging
- The system message "iPhone needs to cool down before you can use it" appears
- The battery health is normal, but the phone still gets burning hot when charging
- Changing the cable and charger didn't make any difference
- The body heats up unevenly—for example, it's hot near the camera or the top part, but cold at the bottom
Uneven heating is a different story. We often see cases where the area near the power management chip gets hot. This is no longer a battery or cable issue—it's a board problem, and you can't figure it out without diagnostics.
If you've tried everything on the list above and nothing helped, come to iClub.pro at ул. Коммунистической 35. Diagnostics are free. A technician will take a look on the spot and tell you exactly what the issue is.