A battery pack , comprising: a cell holder ; a plurality of bus bars positioned at a first end of the cell holder ; and a plurality of battery cells arranged in the cell holder with each of the plurality of battery cells having a first terminal proximate to the plurality of bus bars and a portion of a second terminal proximate to the plurality of bus bars , the first terminal and the portion of the second terminal electrically coupled to the plurality of bus bars at a first end of the battery cell such that the plurality of battery cells is in one of a parallel connection, a series connection, or a parallel and series connection; wherein the plurality of bus bars (214, 216, 218, 222 404, 406, 602, 604, 606) includes: a first bus bar coupled to a first one of the first terminals; a second bus bar coplanar with the first bus bar, the second bus bar coupled to a first one of the second terminals and a second one of the first terminals; and a third bus bar coupled to a second one of the second terminals, the third bus bar disposed over an insulator layer ; characterized in that the insulator layer is disposed over the first bus bar and the second bus bar , wherein the third bus bar is coupled to the second one of the second terminals by a wire extending through aligned apertures of the first bus bar , the insulator layer and the third bus bar . a cell holder ; a plurality of bus bars positioned at a first end of the cell holder ; and a plurality of battery cells arranged in the cell holder with each of the plurality of battery cells having a first terminal proximate to the plurality of bus bars and a portion of a second terminal proximate to the plurality of bus bars , the first terminal and the portion of the second terminal electrically coupled to the plurality of bus bars at a first end of the battery cell such that the plurality of battery cells is in one of a parallel connection, a series connection, or a parallel and series connection; wherein the plurality of bus bars (214, 216, 218, 222 404, 406, 602, 604, 606) includes: a first bus bar coupled to a first one of the first terminals; a second bus bar coplanar with the first bus bar, the second bus bar coupled to a first one of the second terminals and a second one of the first terminals; and a third bus bar coupled to a second one of the second terminals, the third bus bar disposed over an insulator layer ; characterized in that the insulator layer is disposed over the first bus bar and the second bus bar , wherein the third bus bar is coupled to the second one of the second terminals by a wire extending through aligned apertures of the first bus bar , the insulator layer and the third bus bar . a first bus bar coupled to a first one of the first terminals; a second bus bar coplanar with the first bus bar, the second bus bar coupled to a first one of the second terminals and a second one of the first terminals; and a third bus bar coupled to a second one of the second terminals, the third bus bar disposed over an insulator layer ; characterized in that the insulator layer is disposed over the first bus bar and the second bus bar , wherein the third bus bar is coupled to the second one of the second terminals by a wire extending through aligned apertures of the first bus bar , the insulator layer and the third bus bar . <EOS>