Battery charge indication methods, battery state of charge monitoring devices, rechargeable batteries, and articles of manufacture are described. Accordingly, a pedal force of a pedal arm can be easily regulated if necessary. A focus of the laser beam is positioned adjacent at least one surface of the substrate. The clamp assembly allows use of an endoscopic viewing system or can be removed to allow use of a microscopic viewing system in order to view the surgical site in the patient through the working channel.