The LED Hydra emergency pack provides a constant current of 400mA – 500mA to any LED requiring a voltage from 30 to 56Vdc. It uses a 24V 1Ahr nickel-cadmium or 25.9V Lithium-ion battery pack to provide a minimum of 1 hour emergency lighting duration – depending on the wattage of the lamp. The light output will vary depending on the wattage of lamps used. The unit complies with SANS-1464-22. This unit can only be used on LED lamps that have external constant current drivers.