In his teardown, [Ken Shirriff] thoroughly investigates and describes all of the components and circuitry that go into the ubiquitous Macbook charger. Why does it cost $79? Other than the MagSafe ...

This absolute tank of a charger is hugely powerful, with sufficient wattage to charge two 16-inch MacBook Pro laptops at full speed. That makes it a cinch to charge three or even four less ...