Disclosed are an external charger including a solar cell array for charging or powering an implantable medical device (IMD), and a cradle including a solar cell array for charging or powering an external charger for charging or powering an implantable medical device. The disclosed improved external charger or improved cradle are particularly beneficial for charging a battery in an external charger used to charge or power an IMD when a power source is otherwise unavailable, such as a wall socket.