Abstract: A substrate is physically attached to the terminals of multiple different power sources. The substrate includes multiple electrical conductors. Each of the electrical conductors is immobilized along its length relative to the substrate. The electrical conductors include interconnect lines and sensing lines. The interconnect lines provide electrical communication between the power sources. At least one of the sensing lines carries an electrical signal indicating a voltage across one or more of the power sources. Electronics that are immobilized on the substrate employ the electrical signal to determine the voltage across the one or more power sources.

Abstract: The battery pack includes a case that contains batteries and includes terminals through which power from the batteries can be accessed. The battery pack also includes a frame that defines battery receiving compartments that are each configured to receive one of the batteries with the frame immobilizing the position of each battery relative to the other batteries. The frame has a perimeter and at a portion of the frame perimeter serves as an outermost wall of the case.