BATTERY PACK

A battery pack includes: a case that includes an inlet through which a liquid enters the case and an outlet through which the liquid flows out from the case; a holder that is disposed in the case and holds a plurality of batteries; and a plurality of current collector plates that are disposed in the case and electrically connects the plurality of batteries to each other. The holder includes: a body that is disposed apart from the plurality of batteries; and a battery holder that is connected to the body, is made of a material softer than a material of the body, and includes a contact portion that is in contact with the plurality of batteries.