Delete comment from: Ken Shirriff's blog

Harald said...

The Apple 60W adapter outputs 16.5 volt. The 85W one is about 19 volt. Up to 20 volt is safe to feed into the MacBook.
Only the Apple adapters detect the load and only come on once they see the load (provided by a 68k resistor in the MacBook).
All fake adapters I have seen are always on.
I am building a device to test all this.

Dec 24, 2017, 11:30:20 AM

Posted to Teardown and exploration of Apple's Magsafe connector