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Q & A: powering an LED

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Most recent answer: 02/16/2015
Forgive me for not knowing, but I'd like to power a LED rgb bulb with about 3 or 4 AA batteries instead of AC power.The bulb has these specs:Base Type: E27Input voltage: AC 85V-265V. Power: 3Watt. I'm hoping it'll work as it's a very low Watt bulb, but I'm no good at these things, so I have a feeling it won't. The light doesn't need to be bright or even be left on for more than a few hours at any time. Any advice? Thanks for your time
- Colin (age 35)
Huelva, Spain

It sounds like your bulb is designed to work with a high ac voltage. That means it has some circuitry built in to convert that ac voltage to the lower dc voltage that the LED itself uses. Just connecting it to batteries won't work. Instead, you can easily get an inexpensive 3W LED designed to work directly with dc from a battery. They're available for several different socket types, including E27.

If you want to power the bulb for a few hours, you'll either need larger batteries (e.g. a motorcycle battery to work with a 12V bulb) or a lower-wattage bulb. As it happpens, we've discussed some of the options in a very recent post.:

Mike W.

(published on 02/16/2015)

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