direct drive Luxeon III 3W red

[carpio]

Today I tryed to direct drive a red Luxeon 3W LED using a 3.7V li-ion batt and a 1ohm resistor, the bright was good, but when I messure the amps it was only 200mA, so I increassed the voltage and I needed near 10V to reach te 1.4V rated to this LED, what did I do wrong? when I got the 1,4A the voltage at the LED`s pins were 5V!!! I don't understand :(

[eastern57]

Lux II r/o's SHOULD be able to be direct-driven off a Li-Ion battery... so in that respect, you didn't do anything wrong. You might want to check your meter or power source.

And keep in mind, if you measured with the LED attached (and ON), you only read the residual voltage and amperage.