Central Battery Bulkhead (24 / 50 / 110 / 230 Volt AC/DC) -
Emergency Lighting X-FM3/SL/50 LED Slave Recessed Emergency Luminaire 50V AC/DC
Inovec Trading - Tridonic EMconverterLED Series Emergency Battery Kits 50V for LED modules with a forward voltage of 10-54V. 250V for LED modules with a farward voltage of 50-250V. Battery-NiCd, NiMH &
Lighting-Gallery.net - Lamps and Fixtures out and about/Remnants of an old emergency lighting system (50v GLS lamps)