Enlarge / The developers of a new wireless charging tech are thinking big—automobile battery big. (credit: Oak Ridge National Lab) Anyone who has ever left the house without remembering to charge their cellphone can appreciate the concept of wireless power transfer. All you would have to do is remember to drop your phone on your desk, and a wireless charging mat would ensure that it has a full battery by the time you pick it up again. But current wireless charger systems require specialized hardware on both the sending and receiving ends, and power only flows efficiently when the two are a specific (and short) distance apart.