Apple's patent application aims for on-the-go recharging for the Apple iPad using the Smart Cover
To pass the power into the tablet as effectively and efficiently as possible, the Apple iPad would have a receiver that would be coupled with the transmitter in the Smart Cover using the magnets in the latter to perfectly align the two. Charging wouldn't start until the flap is closed, covering the display. Another part of the application describes the table being able to automatically start seeking power from the Smart Cover when the slate is not plugged into an outlet.
The Smart Cover itself does need to be charged in order to power up the embedded batteries. But solar panels are also placed on the outside to collect energy while the user is out and about.
Besides having to add the necessary technology to the Smart Cover, the Apple iPad itself would need to be reconfigured to add the inductive charging circuitry mentioned in the patent, but not included in the current build of the device.
source: USPTO via AppleInsider