Abstract: Provided in the present invention are a battery cluster and an energy storage system, which are applied to the technical field of energy storage. The battery cluster comprises a plurality of battery packs and at least one first fuse, wherein each battery pack is connected to each first fuse in series, so as to form a series branch, and the obtained series branch is connected to a switch box provided with a second fuse. By means of the battery cluster provided in the present invention, at least one first fuse is connected in series in the battery cluster, and the first fuse matches a second fuse in a switch box, so as to realize dual protection; and when the second fuse in the switch box fails, protection can be realized depending on the first fuse, such that the fuse protection reliability is effectively improved, and the safe operation of the battery cluster and the energy storage system is ensured.