A rechargeable battery including an electrode assembly having an inner surface and including a positive electrode, a negative electrode, and a separator interposed therebetween, a case having a space for internally housing the electrode assembly, a cap assembly coupled to the case and electrically connected to the electrode assembly, and a core inside the electrode assembly, wherein the core has a length and includes a plurality of support portions contacting the inner surface of the electrode assembly, and a plurality of avoidance surfaces between the support portions and separated from the inner surface of the electrode assembly.