By john A spontaneous reboot is unsettling at any time, but one that happens specifically while charging narrows the field considerably. Charging places the battery and power circuitry under a load that idle use does not, so a fault that stays hidden during normal operation can surface the moment the cable goes rajaong in. Some causes are trivial; a few are not.
What Is Likely Causing It
- A failing or unstable charger delivers voltage outside the expected range, causing the phone to protect itself by restarting.
- An intermittent cable connection causes rapid connect and disconnect cycles that confuse the power management chip.
- A degraded battery can no longer maintain stable voltage under charge, particularly at higher currents.
- Debris or moisture in the port creates a partial short.
- A software bug in a recent update can cause a crash triggered by the charging state change.
First Steps to Try
- Try a different certified charger and cable, ideally the ones supplied with the phone.
- Power the phone off, inspect the port with a light, and gently remove any debris with a wooden toothpick.
- Charge from a wall socket rather than a laptop, hub, or car adapter.
- Restart the phone and check Settings, System, Software update for a pending fix.
If the Problem Persists
- Charge in safe mode overnight. If reboots stop, a downloaded app is implicated.
- Run the manufacturer’s diagnostic through the support app, focusing on battery and charging tests.
- Wipe the cache partition through recovery if the behaviour began immediately after an update.
- Note whether the phone is unusually warm when it reboots, and record the pattern for a service technician.
Safety and Data Warnings
Stop charging immediately if the phone is hot, the back panel is bulging, or the reboots are accompanied by any smell or discolouration. These are signs of a failing cell, and a swollen battery is a genuine hazard that must be handled by a professional rather than a repair kit from a marketplace. Never use a charger that has been dropped in water or has a damaged plug.
Conclusion
Start with the charger and the port, because a bad supply or a dirty connection explains most charging reboots and costs nothing to rule out. Safe mode separates software from hardware in one night. Any combination of heat, swelling, or reboots under charge is a stop-using-it signal, and that is the one situation here where a service visit should not wait.