A method of controlling charging of a battery (16) of a totally implantable auditory prosthesis and a control system (50) therefor. The method comprises determining a first charge related characteristic of the battery (16) such as the predetermined minimum amount of charge (58), and a second charge related battery characteristic such as the preset charge level or charge rate of the battery (16). The method further comprises detecting when a charge cycle of the battery (16) commences and monitoring where the charge level of the battery (16) is in relation to the first charge related battery characteristic when the charge cycle commences and adjusting the second charge related battery characteristic depending on the relationship between the charge level and the first charge related battery characteristic at the commencement of the charge cycle. The control system and method has the potential to increase the operational life of the battery (16).
