I need to find the right voltage drop of the LED, but came up with problem.. Can i measure the voltage drop if i connect 4,2v batteries straight to the LED and measure the voltage across it. For some reason for the multimeter showed the same voltage across both, red and green LEDs i measured. it showed 2,1 voltage. even thought on the package label, where i bought the led is written, that red led has 2,5V drop and the green- 2.2V. Is there any easy way to find out the actual voltage drop?