It is common for smartphones to get warm while charging. However, excessive heat can sometimes indicate an issue with the phone or charger. In this article, we’ll discuss the reasons a phone may get hot during charging, when the heat is normal versus abnormal, and tips for keeping your phone cool.
Quick Answers
– It is normal for phones to get slightly warm while fast charging or wirelessly charging.
– Using the phone intensively while charging generates more heat and can make the phone hotter.
– Abnormal overheating usually indicates an issue such as a faulty charger, blocked air vents, or a problem with the battery.
– Tips to keep your phone cool include not covering it while charging, turning off features, switching chargers, and replacing old batteries.
Why Does My Phone Get Hot While Charging?
There are a few main reasons why your smartphone may get hot when plugged in:
- Fast charging – Fast chargers work by increasing voltage and amperage to charge the battery quicker. The higher power input generates heat.
- Wireless charging – Inductive wireless charging also operates at higher wattage and is less efficient, producing more heat.
- Normal charging – Even regular chargers make phones slightly warm as the battery is charged.
- Phone use during charging – Using processor-intensive apps or features while charging adds to the heat.
- High ambient temperature – Hot environments can prevent the phone from cooling down properly.
- Faulty charger or cable – Damaged or faulty chargers may overheat and transfer heat to the phone.
- Blocked air vents – Debris or cases that cover air vents prevent heat dissipation.
- Battery age or damage – An old or damaged battery may not charge efficiently, creating excess heat.
When Is the Heat Normal?
It is perfectly normal for your smartphone to get slightly warm while charging. If you notice some warmth coming from the phone, there is usually no need to worry. Here are some scenarios where a warm phone is expected:
- Charging for a long time – Long charging sessions generate more heat over time.
- Fast or wireless charging – These methods produce higher heat but are still safe if used correctly.
- Gaming or video streaming – Using power-hungry apps makes the phone work harder, increasing temperature.
- Hot ambient temperature – The hotter your surroundings, the hotter your phone gets.
- New fast charger – New higher wattage chargers may make the phone warmer until broken in.
As a rule of thumb, the phone should not get uncomfortably hot to touch during regular use. It is also common for some areas like by the camera or upper back to feel warmer. Warmth by itself does not indicate a problem with your phone.
When Is the Heat Abnormal?
While some warmth is expected, excessive heating can be a sign of an issue with your phone or charger. Here are some instances when overheating may be abnormal and dangerous:
- Burning hot to touch – The phone should never be too hot to safely handle and use.
- Very hot even when not in use – An idle phone should not get burning hot.
- Constant overheating – Frequent and consistent overheating is not normal.
- Charging heats up phone – The charger itself should not transfer significant heat to the phone.
- Areas other than usual get hot – Random hot spots may indicate a battery issue.
- Phone feels hot immediately – It should take significant use to make the phone hot.
- Overheating even in cool room – This points to an internal problem.
If your phone exhibits any of these behaviors, it likely indicates a problem that needs attention. Prolonged abnormal high heat can damage phone components and battery capacity.
Is Wireless Charging Safe If Phone Gets Hot?
Wireless charging converts power inefficiently compared to wired charging, so the phone tends to get warmer. However, as long as the phone does not get uncomfortably or unsafely hot, wireless charging is fine to use.
Some steps you can take to keep heat low with wireless charging:
- Use a stand or pad with a built-in fan to dissipate heat.
- Do not use the phone intensely when wirelessly charging.
- Avoid wireless charging for long periods.
- Remove any thick phone case before charging.
- Ensure the charger and phone are properly aligned.
- Switch to a lower wattage wireless charger.
- Check for debris or dirt trapped near the wireless coil.
As with any charging method, monitor your phone temperature. Stop using any charger that causes more than mild, normal warmth.
Is Fast Charging Bad for Battery If Phone Gets Hot?
Fast charging enables incredibly quick charge times by providing more power to the battery. This allows the battery to gain a substantial charge in 30 minutes or less.
The downside is fast charging generates significantly more heat. Fortunately, phones and fast chargers are designed to withstand and dissipate the excess heat of fast charging. So while not ideal for battery health, occasional fast charging likely poses little risk of damage.
Some best practices for fast charging and heat management:
- Avoid using fast charging when battery above 80%.
- Power down phone before fast charging.
- Keep phone as cool as possible when fast charging.
- Avoid prolonged fast charging sessions.
- Allow phone to cool between fast charging.
- Switch to slower charger after phone reaches 50% battery.
Following these tips, your phone battery should withstand normal fast charging with minimal loss in lifespan or capacity.
What Causes Overheating While Charging?
If your smartphone overheats while charging, here are the most common underlying causes:
- Faulty charger – Damaged cables, bad power bricks, and third-party chargers can overheat.
- Poor connection – A loose charging port or insufficient contact with wireless pads causes heat buildup.
- Blocked air vents – Dust, pet hair, debris or thick cases can obstruct ventilation.
- Old lithium-ion battery – Aging batteries charge less efficiently, producing excess heat.
- Broken internal fan – Phones rely on internal fans to distribute heat.
- Excessive phone use – Heavy usage while charging makes the phone work harder.
- Direct sunlight – Charging in hot sunlight prevents cooling.
- Incorrect wireless alignment – Misaligned wireless charging causes overheating.
Finding the specific cause of overheating allows you to take steps to remedy the issue.
How to Keep Phone Cool While Charging
If your phone tends to get hot when charging, here are some tips to keep it cooler:
- Avoid charging in direct sunlight or hot areas.
- Power down phone before charging.
- Remove protective case before charging.
- Never cover or wrap phone when charging.
- Use original charger and cable.
- Check and clear any blocked air vents.
- Switch to standard 5W charger for overnight charging.
- Set phone on cold surface like granite or metal.
- Point a fan at phone to distribute heat.
- Disable CPU-intensive features like high brightness.
Getting into these habits can significantly lower the temperature of your smartphone during charging sessions.
Should You Stop Using Charger if Phone Overheats?
If your phone becomes abnormally hot while charging, it is always best to stop the charging process immediately. Forcing charging to continue risks further overheating damage.
Unplug or remove the hot phone from its charger. Let the phone cool down for at least 15-30 minutes before attempting to charge again. Switch to an alternate cable and charger if possible.
If the phone continues overheating with different chargers and cables, the issue likely lies with the phone itself. Potential causes could be a degraded battery, blocked air vents, or a fan failure.
Avoid charging at all until you can determine and resolve the overheating cause. Forcing charging risks battery damage and dangerous overheating conditions.
When to Be Concerned About Hot Phone While Charging
Mild warmth when charging your smartphone is normal, but excessive heat can be destructive. Be on alert for these signs of abnormal and concerning overheating:
- Phone becomes too hot to handle safely
- Charging port itself feels hot
- Heat concentrated in small hot spots
- Discoloration on back of phone
- Smoke or burning smell from phone
- Phone overheats when not charging
- Constant overheating issues
Any of these indicate a serious problem with your battery, charging components or internal heat management. Do not charge a phone exhibiting these issues until inspected by a repair technician.
How Hot is Too Hot for Phones While Charging?
There is no single maximum safe temperature for smartphones. However, most phone batteries and processors start incurring damage above 113°F (45°C). Prolonged exposure above 140°F (60°C) can destroy battery cells and warp other components.
As a practical guideline, your phone should never become too hot to touch during charging. Any temperature that risks burning your fingers indicates a dangerous issue that should be addressed immediately.
Does Fast Charging Reduce Battery Life?
Yes, fast charging tends to degrade lithium-ion batteries faster than normal charging. However, the impact is quite minor for most users:
- Capacity loss up to 20% higher than standard charging after hundreds of cycles.
- Increased resistance and reduced efficiency over battery lifespan.
- Slightly greater chance of internal shorts and damage.
For moderate fast charging users, the battery should still retain 80% capacity after 500 cycles. The convenience of fast charging outweighs the risks for many consumers.
How to Charge Phone Safely
Follow these tips for safe phone charging to avoid overheating and undue battery wear:
- Use the original charger and cable when possible.
- Inspect charger for damage before each use.
- Do not cover phone or restrict air flow when charging.
- Avoid charging on soft surfaces that insulate heat.
- Keep phone shielded from direct sunlight during charging.
- Refrain from intensive phone use when charging.
- Disable CPU-intensive features like high brightness.
- Consider a phone cooling stand or clips.
Being mindful of heat buildup and taking steps to maximize airflow and dissipation will keep your phone safe. Stop charging if the phone becomes uncomfortably warm.
How to Prolong Battery While Using Fast Charging
You can take measures to mitigate battery degradation when fast charging your smartphone:
- Avoid fast charging past 80% capacity.
- Use slower charger for overnight charging.
- Take phone off fast charger once fully charged.
- Limit fast charging to once or twice per day.
- Don’t fast charge if battery already warm.
- Alternate between regular and fast charging.
- Replace battery once capacity drops below 80%.
Following these best practices, most phone batteries should maintain good lifespan with daily fast charging. Replace the battery every 1-2 years for optimal performance.
Conclusion
It is quite common for smartphones to exhibit mild temperature increases when charging, especially with fast charging. However, excessive or sustained heat usually indicates a problem.
To keep your phone safe, be alert for overheating issues and take steps to maximize heat dissipation. Stop charging immediately if the phone becomes uncomfortably or unsafely hot. With proper care, occasional fast charging presents only minor long-term risks for most users.
