Systems and methods are provided that estimate when to replace a medical device that is implanted in a patient due to battery depletion. These systems and methods significantly reduce the need for service calls made to medical device manufacturers that relate to battery longevity. In some examples, these systems and methods estimate a battery end of life based, at least in part, on an actual battery voltage received on an actual transmission date and a model transmission date determined based on the actual battery voltage. The estimated battery end of life is further based on a comparison of the model transmission date with the actual transmission date.