How to cool down a hot charger

Why chargers get hot

No charger is perfectly efficient. A small share of every watt it delivers is lost as heat inside the case. At 20W that is barely noticeable. At 100W to 160W, running a laptop, a phone and a tablet at once, it adds up to a charger that feels very warm on the outside.

GaN (gallium nitride) chargers are more efficient than older silicon designs, which is why they can be so small. But small also means less surface area to shed heat, so a compact 140W charger can still run warm under a full load.

When hot is a problem

Warm to the touch under heavy load is expected. Stop using the charger and replace it if you notice any of these:

1. 01It is too hot to keep your hand on for a few seconds.
2. 02You smell burning plastic, or the case is discoloured or deformed.
3. 03It cuts out repeatedly, or the cable connector is hot as well as the charger.

Why a hot charger charges slower

Most quality multi-port chargers monitor their own temperature. When the inside gets too hot, they lower their output to protect themselves. You may see this as a laptop that charges at full speed in the morning and noticeably slower after a few hours of heavy use. Keeping the charger cooler helps it hold its rated output for longer.

Seven ways to keep a charger cool

1. 01Give it air on all sides. Don't push it against a wall, under papers, or behind a monitor stand.
2. 02Stand it upright if it is designed to stand. Vertical cases shed heat better than ones lying flat on a desk mat.
3. 03Keep it off soft surfaces. Beds, sofas and thick desk mats trap heat underneath.
4. 04Keep it out of direct sun and away from heaters, PC exhausts and monitors' rear vents.
5. 05Spread the load. If one charger runs a laptop, a tablet and a phone all day, move the phone to a second, smaller charger.
6. 06Use good cables. A cable that isn't rated for the power you are pulling can run warm and limit charging speed. For laptops above 60W, use a 100W or 240W (E-marker) cable.
7. 07Add active cooling. A small fan moving air across the charger's shell is the most effective fix for a desktop charger that runs at high load for hours.

Does a charger cooling fan actually help?

For chargers that spend hours near their maximum output, yes. Moving air carries heat away from the case far faster than still air does, which keeps the charger further from the point where it starts to throttle. The best setups only run the fan when it is needed, so it is silent when the charger is idle.

That is the idea behind our cooling docks: a vented shell shaped around one specific charger, with a temperature-triggered fan and cable bays to keep the desk tidy.

Questions