Origineel bericht door: Suchiththa Wickremesooriya ,
According to Apple's Website -[https://support.apple.com/en-ca/HT201700|Find the right power adapter and cord for your Mac notebook] - you should be fine. According to them "You can use a compatible higher wattage adapter without issue, but it won't make your computer charge faster or operate differently. Lower wattage adapters don't provide enough power." Your computer is rated to use 61W of input charging. At maximum output of your external charger, you've got 1.5X20 = 30W. If anything, your charger is severely underpowered. Apple doesn't seem to have an issue with overpowered chargers, there's probably a failsafe/transformer in the board that automatically down-transforms extra power (Assumption).