Parolees are already subject to many arcane obligations, such as a rigid schedule of meetings and phone calls with the parole officer. The punishment for a sing

Parolees are already subject to many arcane obligations, such as a rigid schedule of meetings and phone calls with the parole officer. The punishment for a single failure is going back to prison for the remainder of the sentence. You could presumably make regular charging of the device a similar requirement. Low battery indicator for too long = back to life in prison.