A battery cell assembly having a cooling fin with a tube, a substantially rectangular-shaped metal plate, first and second cylindrical coupling members, and first and second O-ring gaskets is provided. The tube has an inlet tube portion and an outlet tube portion. The tube is coupled to a peripheral region of the metal plate. The first cylindrical coupling member has a first aperture extending therethrough, and first and second circumferential grooves. The inlet tube portion is disposed in the first aperture and coupled to the first cylindrical coupling member. The first and second O-ring gaskets are disposed in the first and second circumferential grooves, respectively. The outlet tube portion is disposed in the second aperture and is coupled to the second cylindrical coupling member.