A thin metal film battery cell is formed by one or more plates wound in a spiral thereby forming a roll with two ends at which spiralled edges of the plates are exposed. Each end of the roll is covered by an end strap which includes a body of electrically conductive material from which a tab extends. The body contacts each convolution of the roll while leaving a portion of each convolution exposed so that an electrolyte is able to flow into the roll. The tab attached to and projecting outward from the body for making electical connection to the thin metal film battery cell.