A system for pairing a controller and an infusion pump is disclosed. The system includes an infusion pump, a controller device and a user interface residing on both the infusion pump and the controller. The user interface includes a pairing mode for enabling wireless communication between the infusion pump and the controller device, wherein the user interface requires both the infusion pump and the controller to be in the pairing mode simultaneously. Also, a method of changing a power source in an infusion pump is disclosed. The method includes placing the infusion pump in idle mode wherein the infusion pump stops delivery. Removing the first power source from the infusion pump. Replacing the first power source with a second power source in the infusion pump, and maintaining the insulin on board during the changing of the first power source with the second power source.