BATTERY

A battery is disclosed including: a battery body, where a first electrode end plate and a second electrode end plate are disposed at two ends of the battery body respectively, a connecting sleeve is disposed on the first electrode end plate, and the second electrode end plate has a contour edge extending along a length direction of the battery body and away from the battery body, to define a first mounting countersink; and the connecting sleeve can be detachably connected to a first mounting countersink of another battery, and the connecting sleeve has an electrical contact surface at a free end that is in surface contact with the second electrode end plate.