Abstract: An energy storage device includes: a cell holder assembly; energy storage cells disposed in the cell holder assembly; and interconnect members that connect with the energy storage cells. The interconnect members include: double row interconnecting structures disposed on opposite sides of the cell holder assembly; and a pair of single row terminal interconnecting structures that border the double row interconnecting structures on both sides. Each of the interconnect members includes a first independent metallic layer member and a second independent metallic layer member that are electrically coupled to each other and that electrically connect to the energy storage cells. The first independent metallic layer member is an upper member of each interconnect member that connects the interconnect member with a battery management system (BMS). The second independent metallic layer member is a lower member of each interconnect member that connects the interconnect member with the energy storage cells.