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The title of this listing says 3W:

http://www.ebay.com/itm/50PCS-3W-RED-80lm-640nm-LED-Plant-Glow-Light-Emitter-with-20mm-star-base-/221518318191?pt=LH_DefaultDomain_0&hash=item3393854a6f

But the specs that follow show a forward voltage (max) of 2.4V and forward current of 700mA. Wouldn't the power in this case be 2.4V * 0.7A = 1.68W and not 3W?

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  • \$\begingroup\$ Seems more like a question that is related to marketing rather than electronics design. Is there some way you could re-word this so that there is some sort of technical implication of designing for 1.68W instead of 3W? \$\endgroup\$
    – Funkyguy
    Aug 18 '14 at 18:52
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    \$\begingroup\$ Do you have a datasheet? It's likely max pulse power at 10% duty cycle or something similar. \$\endgroup\$
    – ACD
    Aug 18 '14 at 18:53
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    \$\begingroup\$ I always ask questions of the seller if they advertise anything that way... \$\endgroup\$ Aug 18 '14 at 18:55
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    \$\begingroup\$ Don't buy anything that doesn't have a proper pdf data sheet is my policy. \$\endgroup\$
    – Andy aka
    Aug 18 '14 at 19:30
  • \$\begingroup\$ The only information I have is from the ebay listing itself. I just wanted to make sure that I wasn't missing something about how I was doing my calculation, since my result was not 3W. \$\endgroup\$ Aug 18 '14 at 19:33
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It is most likely the maximum TDP (Thermal Design Power) of the LED, given the substrate/heatsink the actual diode is mounted to.

You should probably contact the seller though, since they might have just screwed up.

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