Battery module having restrainer and method of fixing restrainer

A battery module in which a plurality of batteries (1) are connected in a battery unit (10) and a method of fixing a restrainer (40), the battery module including a pair of end plates (50) facing each other; a restrainer (40) coupled to the pair of end plates (50), the restrainer (40) being configured for restraining expansion of the battery unit (10); and a coupling unit for coupling the end plates (50) and the restrainer (40) to each other, wherein the coupling unit includes a variable position coupling device (B) configured to fix the restrainer (40) and the end plate (50) while varying a coupling location between the restrainer (40) and the end plate (50).