I've got a 2017 MacBook Pro which comes stock with an 87W USB C Power Adapter.
I want to purchase an additional power adapter, but I don't require an official Apple one. I notice that Anker make one with 60 W power output over USB C.
Other than charging my laptop at about 2/3rds the speed of the Apple Power Adapter, (2/3rds = ca. 60/87 w), would there be any effect / damage on my machine?
Best Answer
The USB-C plug is not the problem, but the charger is.
It is underrated, so it will never manage to completely charge your battery while the Mac is in use, or supply enough when needed.
With that said, you can use it to charge battery overnight to use it during the day.
To verify it is best to take occasional look at the battery charge condition in "System information" (hold the "option" key and click on the apple symbol on the top left corner on the menu bar).
This indicated value will be negative if charger is not plugged in or not sufficient.
It will be positive if charger is sufficient.
No damage to your Mac will occur in any case.