The B4CFG emergency ballast works in conjunction with an AC ballast to convert new or existing fluorescent fixtures into emergency lighting. The emergency ballast consists of a high-temperature nickel-cadmium battery, charger and electronic circuitry in one compact case. The B4CFG can be used with one 13 - 42 W twin, quad or triple twin-tube lamp, one 22 - 40 W T5 circline or one 18 - 39 W long compact fluorescent lamp. It is also compatible with most one-, two-, three- and four-lamp electronic, standard, energy-saving and dimming AC ballasts. The B4CFG is suitable for indoor and damp locations and for sealed gasketed fixtures, including fixtures rated for wet locations. It is not suitable for air handling heated air outlets or wet or hazardous locations.