In one aspect, a battery pack has a cooling assembly. The cooling assembly includes a first flow channel structure and a second flow channel structure. A liquid outlet of the first flow channel structure is configured to be in communication with a liquid inlet of the second flow channel structure; and the first flow channel structure is configured to dissipate heat for a non-pole region of a battery set, and the second flow channel structure is configured to dissipate heat for a pole region of the battery set.