A retrofitting, inductive-battery-charging device for use with a surgical sterilization device, comprising an inductive charging assembly and an inductively powered battery-charging platform that is sterilizable inside a surgical sterilization device and is operable to charge at least one rechargeable battery of a battery-operated surgical instrument when the rechargeable battery is placed at the platform. The inductive charging assembly comprises an inductive-power-supply sub-assembly electrically connected to a power supply and is operable to supply power inductively over a distance at least equal to a width of a wall of the surgical sterilization device, and an inductive-power-receiver sub-assembly that is sterilizable inside the surgical sterilization device and electrically coupled to the platform. The inductive-power-receiver sub-assembly is operable to supply charging power to the platform for charging the at least one rechargeable battery when placed at the platform, and to inductively receive electrical power from the inductive-power-supply sub-assembly at least over the distance.