Why Does a Smartphone Heat Up While Charging and How to Fix It
Modern smartphones are equipped with powerful batteries and fast charging features that significantly reduce the time spent connected to a power outlet.
Why Does a Smartphone Heat Up While Charging and How to Fix It
Modern smartphones are equipped with powerful batteries and fast charging features that significantly reduce the time spent connected to a power outlet. However, this often comes with the issue of heating during charging. Mild warmth is normal, but excessive heat can negatively affect battery life, device performance, and even safety.
Main causes of heating:
- Using the phone while charging — launching games, videos, calls, or navigation creates additional load on the processor, which is simultaneously being powered and discharged.
- Fast charging (Quick/Adaptive/Fast Charge) — the charger supplies increased voltage (9V–12V) instead of the standard 5V. This speeds up charging but also raises the temperature of the power controller and the battery itself.
- Non-original chargers or cables — may supply unstable voltage, causing overheating or battery damage.
- Battery wear — as capacity and chemical stability decrease, the battery heats up more. There may also be issues with the PMIC (Power Management IC).
What is considered normal?
- Case temperature up to 40°C is acceptable.
- If the smartphone feels too hot to touch or shuts down during charging — this is abnormal.
- In standby mode, the smartphone should not heat up at all.
How to reduce heating?
- Do not use the smartphone while charging, especially for resource-intensive tasks.
- Remove the case — some silicone or plastic models trap heat.
- Only use the original charger and a certified cable (USB PD, QC).
- Avoid external overheating — do not charge in direct sunlight, under a pillow or blanket.
- Update firmware — some manufacturers fix power management algorithms.
When to contact a service center?
- The smartphone heats up even in standby mode.
- Charging causes freezing, restarts, or shutdowns.
- You notice a burning smell, swollen case, or deformation.
- The battery drains quickly after charging.
Smartphone heating is not always a sign of malfunction, but regular overheating shortens battery lifespan and poses risks. If you notice your device heating more than usual — don’t delay. At the F1Center service center, we’ll perform a precise diagnosis, check the battery, power controller, and provide recommendations for safe usage.