A medical system comprises an implantable medical device having a power source, the implantable medical device configured for monitoring a quantity of the stored energy in the power source, generating a battery status signal based on the monitored quantity of stored energy, and for transcutaneously transmitting a communication initiation signal and the battery status signal. The medical system further comprises an external device configured for transcutaneously receiving the communication initial signal and the battery status signal from the rechargeable implantable medical device, changing from a relatively low energy consumption state to a relatively high energy consumption state in response to the received communication initiation signal, and for generating a user-discernible signal in response to the received status signal.