CFL and LED Bulbs on DC?

Most recent answer: 03/26/2015

We have a 125 VDC battery bank used to power some emergency equipment and need emergency lights. We've used standard incandescent bulbs in the past. To reduce drain on the batteries, will standard 120VAC screw-in CFL or LED replacement bulbs work when powered by 125VDC?
- Garry Upton (age 40)
Little Rock, AR, USA

No, those bulbs come with built-in circuitry designed for ac power. LED's themselves run off dc, so depending on how your circuits look perhaps you could adapt them to have many 12V dc outlets. 12V dc LEDs are easily available. Maybe 120V dc ones are too. Another possibility is to use an inverter to get ac power out of your batteries for use with either standard CFL's or LEDs, but that seems like an unnecessary inefficiency.

Mike W.

(published on 03/26/2015)