Disclosed in an improved medical implantable device system including an improved external charger that is able to communicate with an external controller and IPG using the communication protocol (e.g., FSK) used to implement communications between the external controller and the implant. The external controller as modified uses its charging coil to charge the implant, and also to communicate with the other devices in the system. As such, the external charger is provided with transceiver circuitry operating in accordance with the protocol, and also includes tuning circuitry to tune the coil as necessary for communications or charging. Communication or charging access to the charging coil in the external charger is time multiplexed. The disclosed system allows charging information to be provided to the user interface of the external controller so that it can be reviewed by the user, who may take corrective action if necessary. Also disclosed are schemes for synchronizing and arbitrating communications between the devices in the system.