A battery module, comprising: a first set of battery cells stacked in a first direction and a second set of battery cells stacked in the first direction, the first and second sets of battery cells being arranged in a second direction and facing in opposed directions relative to each other; and at least one battery cell holder between adjacent battery cells in at least one of the first and second sets of battery cells stacked in the first direction, the battery cell holder including: an insulating plate between the adjacent battery cells in the at least one of the first and second sets of battery cells stacked in the first direction, wherein the insulating plate includes a plurality of protrusions, which optionally include upper protrusions facing a first surface of one adjacent battery cell and lower protrusions facing a second surface of another adjacent battery cell and wherein the insulating plate with the guides thereon has an overall rectangular shape for co-operation with prismatic battery cells, wherein the insulating plate includes a metal plate, the upper and lower protrusions include a metal, wherein insulating layers cover the metal plate, the upper protrusions, and the lower protrusions, and a plurality of guides protruding from edges of the insulating plate to extend in the first direction over the adjacent battery cells in overhanging relationship therewith. a first set of battery cells stacked in a first direction and a second set of battery cells stacked in the first direction, the first and second sets of battery cells being arranged in a second direction and facing in opposed directions relative to each other; and at least one battery cell holder between adjacent battery cells in at least one of the first and second sets of battery cells stacked in the first direction, the battery cell holder including: an insulating plate between the adjacent battery cells in the at least one of the first and second sets of battery cells stacked in the first direction, wherein the insulating plate includes a plurality of protrusions, which optionally include upper protrusions facing a first surface of one adjacent battery cell and lower protrusions facing a second surface of another adjacent battery cell and wherein the insulating plate with the guides thereon has an overall rectangular shape for co-operation with prismatic battery cells, wherein the insulating plate includes a metal plate, the upper and lower protrusions include a metal, wherein insulating layers cover the metal plate, the upper protrusions, and the lower protrusions, and a plurality of guides protruding from edges of the insulating plate to extend in the first direction over the adjacent battery cells in overhanging relationship therewith. an insulating plate between the adjacent battery cells in the at least one of the first and second sets of battery cells stacked in the first direction, wherein the insulating plate includes a plurality of protrusions, which optionally include upper protrusions facing a first surface of one adjacent battery cell and lower protrusions facing a second surface of another adjacent battery cell and wherein the insulating plate with the guides thereon has an overall rectangular shape for co-operation with prismatic battery cells, wherein the insulating plate includes a metal plate, the upper and lower protrusions include a metal, wherein insulating layers cover the metal plate, the upper protrusions, and the lower protrusions, and a plurality of guides protruding from edges of the insulating plate to extend in the first direction over the adjacent battery cells in overhanging relationship therewith.