Charging MacBook Air with a fast charger from usb-c I have a MacBook Air 2020 and forgot my charger at work. Evidently I need to charge it in a few hours. I have One Plus phone with a fast charger which is USB-C compatible (5V, 4A). Could I use it to charge the MacBook Air?  Does this damage the mba ?
It shouldn't damage anything, but it might not be powerful enough to keep up.
The Macbook Air charger is 30w, which is about 6A.
Amps are &quot;pulled&quot; by the computer rather than &quot;pushed&quot; by the power supply [which is the opposite to voltage; this is why voltage has to match but amperage doesn't] however, your charger will be incapable of supplying all the Mac is asking.
This will just make charging slower. If you're lucky, it might just keep up, otherwise the battery might still lose charge slowly while the Mac is in use, even with the charger connected.