Estimating LED lumen output using before and after bat. volts.

[spinnor]

The good news is the lens on the light allows me to get a good magnified view of the LED. From a review of LEDs on budgetlightforum,

Cree, Luminus, Seoul Semiconductor, and Nichia LED comparison

I would suggest reading my guide on tint, binning, and CRI before reading this. This is a comparison between all of the common LEDs. The LEDs included are: XP-G, XP-G2, XM-L, XM-L2, XR-E, XP-E, XP-E2, Nichia 219, SSC-P7, MC-E, SST-50, SST-90, MT-G2 XP-G The XP-G is a small Cree LED that is 3.45 mm by 3.45mm. The size of the die is 1.4mm by 1.4mm for a total die surface of 1.96mm2 which is often simplified to 2mm2. It is distinguishable by it's size and the grid of 4 strips. [image] It has…

it looks like I have the XM-L T6. Will experiment and try and work backwards to estimate efficiency.

Thanks all!

Edit. From the picture all I guess I can tell is I have a XM-L and not the particular version.

Edit. On the other hand the color of the light seems to be cool white which would favor it being a T6?

Edit. Cool white models of XM-L could be T6, T5, or U2, all powerful emitters.