Emmerich 24d4000s emergency lights battery 2 4v 4000mah emmerich 24d4000s p the emmerich 24d4000s is an emergency lights battery rated at 2 4v 4000mah this nickel cadmium nicd battery pack is ideal for escape route lighting security and emergency lighting the battery has a 2x in line battery configuration and is both universal and suitable for use in most brands of emergency lighting p emmerich 24d4000s emergency lights battery 2 4v 4000mah