The BEWAG battery was the largest battery for utility applications in the world at the time it was commissioned. It was installed to provide frequency regulation and spinning reserve to the West Berlin grid when East and West Berlin were still divided, which technically created an electrical "island" grid since West Berlin was not connected to the grid in Western Europe. The battery system operated in the multifunction frequency regulation adn spinning reserve mode until 1993, when the frequency regulation mode was no longer needed after the reunification, and West Berlin was connected to the European grid.

The battery remained in operation until 1995, in the spinning reserve mode, when it reached its end of life.

Lead-acid Battery