Methods and systems for transfer-switch controller backup and transfer-switch controller operation are provided. An example backup apparatus includes a memory configured to store transfer-switch data related to a first transfer-switch controller, wherein the first transfer switch-controller is a controller for a given transfer switch. The apparatus is capable of interfacing with a communication interface of the first transfer-switch controller. The apparatus is further capable of being removed from the communication interface of the first transfer-switch controller and thereafter interfacing with a communication interface of a second transfer-switch controller, wherein the second transfer-switch controller is a replacement controller for the given transfer switch. The memory is further configured to, after the apparatus interfacing with the communication interface of the second transfer-switch controller, provide the transfer-switch data related to the first transfer-switch controller to the second transfer-switch controller.