A battery can include an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode. The first electrode can have a pair of first sides and a pair of second sides extending between the pair of first sides, a first portion including an active material extending between the pair of first sides, and a second portion extending between the pair of first sides and exposed beyond the separator along a winding direction. The battery can further include a battery housing having a first opening at a first end and a second end with a second opening opposite the first end, a first current collector including a support portion positioned on the electrode assembly, and a housing cover which seals the first opening.