Abstract: Systems and methods for accurately determining the state of charge and the relative age of lithium sulfur batteries are provided. The cell resistance and taper input charge of a particular type of lithium sulfur battery are respectively measured to determine the state of charge and age of the battery.

Abstract: A connector assembly connects a plurality of battery cells in a serial/parallel arrangement. Each battery cell includes a cover and a canister having a side and a bottom. Each battery cell is constructed such that a segment of the side of the canister forms a top crimped portion that retains the cover and is electrically isolated from the cover. The connector assembly includes a conductive weld cup. The conductive weld cup includes a bordered portion and recessed portion. The bordered portion includes a first side wall and a ledge that is substantially planar. The recessed portion is recessed within the ledge. The recessed portion includes a recessed portion and a floor that is substantially planar. The first side wall includes an integrated tab projecting from it. An inner surface of the bordered portion engages an outer surface of the side and the bottom of the canister of an upper adjacent battery cell. An outer surface of the floor engages a cover of a lower adjacent battery cell.