Self-winding watches have been around for decades, but now Apple wants to take some of that thinking and use your body movements to keep your tech charged up.
The patent describes how they plan to "harness electrical power using electromagnetic induction utilizing printed coils," and sounds kind of similar to the system Seiko has been using in their Kinetic watch series since the late 1980s. Come to think of it, we've even seen another cellphone that uses something pretty darn similar.
The key difference is that rather than using motion of a rotating weight to generate power, the Apple system has the actual magnets moving directly in front of the generating coils. So it should work with smaller degrees of motion than are needed to get that big weight spinning around. The downside is that the power generated will be less, so Apple sees this as a way to extend the life of a charge, rather than replacing it.
Of course there are plenty of other ways you can use your body's motion to power up your portable tech.