Abstract: A secondary battery includes a container; an electrode assembly having a positive plate, a negative plate, and a separator interposed between those two plates. The electrode assembly is mounted inside the container and a cap assembly is fixed to the container to seal the container. A positive collector plate and a negative collector plate are electrically connected to the positive and negative plates of the electrode assembly. At least one collector plate of the positive and negative collector plates includes a plate-shaped body and a contact portion projecting from the body to contact the collector of the corresponding plate.