The battery was later developed by the Irish chemist Dr. James J. Drumm (1897–1974), and installed in four two-car Drumm railcar sets between 1932 and 1949 for use on the Dublin–Bray railway line. Although successful, they were withdrawn when the batteries wore out. Early nickel–zinc batteries provided only a small number of discharge/recharge cycles. In the 1960s nickel–zinc batteries were investigated as an alternative to silver–zinc batteries for military applications, and in the 1970s were again of interest for electric vehicles. Evercel Inc. developed and patented several improvements in nickel–zinc batteries, but withdrew from that area in 2004.Evercel financial statement 2007 , Evercel.com, page 9, Retrieved 23 November 2010.
