Charging a battery of an implanted device involves positioning an external charging coil proximal to a charging locale. An implant recipient and the implanted device are expected to occupy the charging locale from time to time. The charging coil has a coil area which is significantly larger than a coil area of an implanted coil, and is configured to produce an electromagnetic field throughout the charging locale. When an implant recipient is within the charging locale, the external charging coil is driven with a signal which transmits electromagnetic power from the charging coil to the implanted coil.
