Abstract: Devices, systems, and techniques for selecting a period for charging an implantable rechargeable power source are disclosed. Implantable medical devices may include a rechargeable power source that can be transcutaneously charged. A system may control a charging module to begin charging the rechargeable power source of the implantable medical device with a high power level. The system may then determine an estimated heat loss based on power initially delivered to the rechargeable power source when beginning the charging. Based on this estimated heat loss during the initial period of recharging, the system may select a boost period that includes a duration of time that the rechargeable power source is charged with the high power level.

Abstract: This disclosure describes techniques for a method of charging a battery. In an example, the method includes charging the battery during a first charging session until a first charging termination parameter value is reached. The method also includes determining, for a second charging session, a second charging termination parameter value based on a duration of the first charging session, wherein the second charging termination parameter value is different than the first charging termination parameter value. The method also includes charging the battery during the second charging session until the second charging termination parameter value is reached.

Abstract: Devices, systems, and techniques for controlling charging power based on a cumulative thermal dose to a patient are disclosed. Implantable medical devices may include a rechargeable power source that can be transcutaneously charged. An external charging device may calculate an estimated cumulative thermal dose delivered to the patient during charging over a predetermined period of time. Based on the estimated cumulative thermal dose, the external charging device may select a power level for subsequent charging of the rechargeable power source. In one example, the charging device may select a high power level when the cumulative thermal dose has not exceeded a thermal dose threshold and select a low power level when the cumulative thermal dose has exceeded the thermal dose threshold.

Abstract: This disclosure describes techniques for a method of charging a battery. In an example, the method includes determining a capacity of the battery, and determining a state of charge of the battery. The method also includes charging the battery with a charging current, wherein the charging current is based on the capacity of the battery and the state of charge of the battery, and wherein charging the battery comprises reducing the charging current in response to the state of charge of the battery changing with respect to the capacity of the battery.

Abstract: Far field telemetry communications are conducted during recharge sessions between an external device and an implantable medical device. The two devices may not have been previously paired together for far field telemetry and may have been paired with other devices for far field telemetry during previous recharge sessions and/or programming sessions. Embodiments provide for temporary bonding of the two devices for far field telemetry during the recharge session. The implantable medical device of the recharge session may maintain a programming bond with an external device other than the external device conducting the recharge session. Safeguards against establishment of inadvertent programming sessions between the external device that has conducted a recharge session and implantable medical devices that may or may not be bonded to that external device are provided.