Abstract: A lithium iron phosphate battery pack is disclosed. The battery pack includes a plurality of battery cells, arranged as groups of cells, a controller circuit, and a plurality of intercell tabs coupling the groups of battery cells to the controller circuit. The controller circuit includes a voltage sensor for monitoring the voltage across each of the groups of cells. If one of the groups has a voltage that is lower or higher than a respective lower or upper threshold voltage, the controller circuit will shut off the charge/discharge cycling of all the groups of cells. In doing so, the controller circuit protects the entire battery pack during charge/discharge cycling.

Abstract: A lithium ion battery pack including a housing and a top attached to an open end of the housing is disclosed. The battery pack includes plurality of battery cells, arranged in parallel and contained in the housing. The battery pack further includes cathode and anode current collectors. Each of the current collectors includes a collector plate welded to a collector plate tab. The collector plate tabs are welded to the respective cathode and anode covers of the battery cells.