Do I have the power???

[Darth Tollo]

I have a left over 2AA battery holder. Can it power a 3w LED?

[xwingband]

You can direct drive any III with that. A red/Amber would do just as well as with a resistor, but a Blue/Green/White wouldn't be nearly as hot.

If you used a Boostpuck or another "step-up" drive you'd be cool too.

[Darth Tollo]

Sweet. I wanted to do amber anyway. Thanks.

[Novastar]

For the record, "3w" is a misnomer, but yes, a red, red-orange or amber Luxeon III LED has a 2.95 fwd voltage, meaning if you give it about 3v, it should be "happy" and light up near its best brightness.

A Lux III blue, royal blue, cyan, green, etc. is more like 3.4 or 3.8 volts forward I think... so it won't be as "happy"... but will still be relatively fine.