A battery module (28, 30), comprising: - a battery cell stack (40, 42) disposed within a housing of the battery module (28, 30); - a first battery cell of the battery cell stack (40, 42) comprising a first casing and a first terminal; and - a second battery cell of the battery cell stack (40, 42) positioned adjacent to the first battery cell and comprising a second casing and a second terminal; - a battery cell separator fitted over the first battery cell, wherein the battery cell separator comprises a plurality of walls and a projection (66, 70) extending from a wall of the plurality of walls: wherein the plurality of walls is formed from a continuous material and defines a pocket in which the first battery cell is disposed, and the plurality of walls is configured to electrically insulate the first casing from the second casing; wherein the plurality of walls of the battery cell separator comprises a first wall, a second wall, and a third wall connecting the first and second walls (92, 94), wherein the second wall is disposed opposite to the first wall, wherein the third wall is disposed over a terminal side of the first battery cell, the first terminal extending from the terminal side; wherein the first wall of the battery cell separator is disposed between a face of the first casing of the battery cell and a face of the second casing of the second battery cell and separates the face of the first casing from the face of the second casing; and wherein the projection (66, 70) is positioned between the first and second terminals (64, 68) and is configured to electrically insulate the first terminal from the second terminal. - a battery cell stack (40, 42) disposed within a housing of the battery module (28, 30); - a first battery cell of the battery cell stack (40, 42) comprising a first casing and a first terminal; and - a second battery cell of the battery cell stack (40, 42) positioned adjacent to the first battery cell and comprising a second casing and a second terminal; - a first battery cell of the battery cell stack (40, 42) comprising a first casing and a first terminal; and - a second battery cell of the battery cell stack (40, 42) positioned adjacent to the first battery cell and comprising a second casing and a second terminal; - a battery cell separator fitted over the first battery cell, wherein the battery cell separator comprises a plurality of walls and a projection (66, 70) extending from a wall of the plurality of walls: wherein the plurality of walls is formed from a continuous material and defines a pocket in which the first battery cell is disposed, and the plurality of walls is configured to electrically insulate the first casing from the second casing; wherein the plurality of walls of the battery cell separator comprises a first wall, a second wall, and a third wall connecting the first and second walls (92, 94), wherein the second wall is disposed opposite to the first wall, wherein the third wall is disposed over a terminal side of the first battery cell, the first terminal extending from the terminal side; wherein the first wall of the battery cell separator is disposed between a face of the first casing of the battery cell and a face of the second casing of the second battery cell and separates the face of the first casing from the face of the second casing; and wherein the projection (66, 70) is positioned between the first and second terminals (64, 68) and is configured to electrically insulate the first terminal from the second terminal. wherein the plurality of walls is formed from a continuous material and defines a pocket in which the first battery cell is disposed, and the plurality of walls is configured to electrically insulate the first casing from the second casing; wherein the plurality of walls of the battery cell separator comprises a first wall, a second wall, and a third wall connecting the first and second walls (92, 94), wherein the second wall is disposed opposite to the first wall, wherein the third wall is disposed over a terminal side of the first battery cell, the first terminal extending from the terminal side; wherein the first wall of the battery cell separator is disposed between a face of the first casing of the battery cell and a face of the second casing of the second battery cell and separates the face of the first casing from the face of the second casing; and wherein the projection (66, 70) is positioned between the first and second terminals (64, 68) and is configured to electrically insulate the first terminal from the second terminal.