How Wireless Charging Works: The Physics Behind Power Transfer Through Air
On September 2, 1897, Nikola Tesla filed a patent for a system of electrical transmission without wires. His vision was ambitious: power delivered through the air to homes and factories, eliminating the need for electrical infrastructure entirely. Over a century later, wireless charging exists—but it works nothing like Tesla imagined. The technology that powers modern smartphones operates on principles far more constrained, yet far more practical. Understanding wireless charging requires grasping a fundamental truth: no energy travels “through the air” in the way radio waves or light do. Instead, wireless charging creates a magnetic field that couples two coils together, forming what amounts to a split-apart transformer. The energy still follows paths defined by electromagnetic field lines—it simply crosses a small air gap rather than flowing through a solid iron core. ...