A ballast with circuitry to allow the level of the lighting device to be adjusted, a separate direct current input and a sensing circuit within the ballast to lower the light level and thus the amount of power required from the direct current input when the normal line power fails. The system includes placing a sensing device within the ballasting circuitry housing and using a fiber optic conductor to conduct the light into the ballast from an external source. The system further includes recharging the battery by supply current to flow out of the direct current input when the ballast is operating from line power.