Intended for hazardous locations that require fail-safe lighting, HAL-EMG-EXT-12W-2L features integral Nickel-Cadium battery backup power supply that is protected from deep discharge by solid-state circuitry. In case of power outage, Class 1 Division 2 unit automatically switches to battery backup for 90+ min or until power is restored. When power is restored, built-in charger returns unit to fully charged state. System operates from 120–277 V and withstands temperatures from 0 to +50°C.