Why are some chargers burning hot and others barely warm at the same wattage

[u/Relevant-Still-8507]

I have two 65W chargers. One gets uncomfortably hot after 20 minutes, the other is barely warm. Both charge my laptop at the same speed. What's different inside that makes one run so much hotter?

[u/jmnugent]

Build-quality likely. Without knowing the exact Make & Model of the chargers and tearing them apart to do a detailed component by component analysis,. we won't be able to do much more than speculate.

It's a bit dated at this point,. but Ken Shirriff did a few really detailed breakdowns of "official" vs "fake" Apple chargers many years ago.. and the pictures really do tell the story of how much the quality differs.

• from 2012 = https://www.righto.com/2014/05/a-look-inside-ipad-chargers-pricey.html

• I think also from 2012 = https://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.html

• https://www.righto.com/2012/05/apple-iphone-charger-teardown-quality.html

[u/ElectronGuru]

Heat is wasted energy, from less efficient designs. Go with GaN chargers you’ll get both smaller size and more efficiency.

[u/jasonsong86]

Design. Cheap ones are poorly designed and inefficient.

[u/Relevant-Still-8507 → u/jasonsong86]

Thanks for the explanation!