A secondary battery includes an electrode assembly for generating electricity, a can for accommodating the electrode assembly, and a cap assembly. The can has an open top and the cap assembly seals the open top. The electrode assembly has a plurality of electrode tabs through which electricity is supplied. The cap assembly includes an insulating case that has a plurality of tab drawing grooves. Each of the tab drawing grooves is capable of being occupied by one of the electrode tabs. A number of the tab drawing grooves is greater than a number of the electrode tabs. One of the electrode tabs can be drawn through one of the tab drawing grooves. Other tab drawing grooves are left as spare grooves, and therefore it is not necessary to change the shape of the insulating case even though the structure of the secondary battery is changed.