BATTERY MODULE

To improve reliability of a battery module, battery module () includes battery stack () having a plurality of batteries () stacked, each battery () having a top surface provided with an output terminal, restraining member () that has flat portion () extending along side surfaces of the plurality of batteries () in stacking direction (X) of batteries () and restrains the plurality of batteries (), and side separator () that has first portion () interposed between each battery () and flat portion () and insulates each battery () from flat portion (). Each battery () is disposed with gap (G) from first portion (), the gap being large enough to suppress movement of water (W) due to capillarity.