About your portable Mac computer’s power adapter
If you have a portable Mac computer, plugging in the power adapter provides power to the computer and recharges the computer’s battery. For optimal performance, use the power adapter that came with your portable computer—either a MagSafe or USB-C—or a compatible replacement adapter. You can purchase a compatible replacement adapter from apple.com or an Apple Store.
About MagSafe power adapter light colors
When you first connect a MagSafe power adapter to a compatible computer, the adapter light glows green for about a second to indicate that power is available. After that, the adapter light glows green or amber.
Green: A steady green light indicates that the battery is fully charged.
Amber: A steady amber light indicates that the battery is being charged.
To learn more about your computer’s battery, see Manage your portable Mac computer’s battery.