[nextaccountic]

What about laptops that charge from USB-C?

[ajb]

They generally use PD which they negotiate up to 20V. Theoretically they should also charge off lower voltages as well, not sure if they bother.

[pletnes]

My macbook charges on 9V phone chargers. Slooowly.

[gorbypark]

I love the “new” MagSafe charger on my MacBook Air but also love that I can grab a charge from any random USB-C charger and cable if I need to. I regularly charge from a little 18w charger that I use for my phone.

It’s enough to keep the thing going without draining the battery and will charge it overnight fully. It’s pretty great having the option.

[paraselene_]

USB-C has been great, I now daily carry a 30w pd charger that's basically the same size as those old 5w iphone ones. Works great as a fallback option in a pinch.

[jon-wood]

You can even charge a MacBook from another MacBook if you happen to find yourself in a situation where you forgot the power adapter but not a USB-C cable.

[iakov]

How do the devices negotiate who gives the charge and who gets charged? I’ve never tried it - I imagined it wont work at all!

[jon-wood]

I have no idea, but the device that was plugged into mains power was very happy to pass some of it on to my laptop.