The invention relates to a battery changing system comprising an industrial truck and a battery pack, which is or can inserted into a battery compartment of the industrial truck, wherein the battery pack may be inserted into a lateral access opening of the battery compartment with a first end leading into the battery compartment and may be withdrawn from the battery compartment with its first end at the rear, wherein the battery pack accommodated in the battery compartment can be supported in the vicinity of its first end with at least one rolling body on the base of the battery compartment, and at least one transport device, on which the battery pack can be accommodated. The transport device may comprise a changeable adapter, which can be aligned in a predetermined position for a battery changing operation relative to the industrial truck by means of mutually interacting alignment means.