These 10W LEDs are sold as 950lumen or am I wrong.
Please add also the ground earth of your power socket to the metal part of the floodlight housing.
They were sold as 1000 lumen, I think. Chinese lumens, that is.
And yes, part of my review will be to point out the lack of earth ground to the case. There isn’t an easy way to add it, short of drilling a hole and adding a self-tapping screw or nut and bolt. On one I used the retaining nut, but it’s not the best connection to use.
Sorry for resurrecting old thread, but I found these generic 10W emitter on sale on Aliexpress for the next 2 days:
$7.33 per lot of 10, fress shipping, that’s only 73cents apiece. Cheapest price I’ve seen. These are probably not very suitable for flashlights - but especially useful for other 12V applications e.g fish tank, car internals etc.
Or lawnmowers. Easier to just use 12V emitter, ya know, instead of messing aroung with AC/DC/converters and stuff 
Hey! You making fun of my build???
-Garry
Those emitters still need some type of driver…
Yes, cheap driver a.k.a resistor. 2ohms will do. 
14V (alternator DC) - 12V (Vf) = 2V, absorbed by 2ohm = 2V^2V / 2ohm = 2W power loss. Provides 1A current -> assuming 10W power on LED, this is already 10W / (10+2)W = 83% efficient. Good enough for extra cheap solution, eh?
So buy 2pcs of 4ohm, 1W resistor (around $1.50 ebay per 20pcs) and stick em parallel together with heatsink. Got your 83% efficient 15 cents driver.
What? Why would you say that? I named no names…
Just kidding anyhow. But sometimes simpler can just be better.
Cool. The warm white emitters put out a gorgeous light. I thought they needed about 9 volts. Two of them connected in series to at 18 v laptop power supply will light a big room in beautiful light. Couldn't resist and ordered a set. Thank you for reporting the find Pulsar13. 
The Vf on these arrays is around 9.6V, not 12V. Also, do you trust your lawnmower alternator to put out a regulated, constant, spike-free 14.4V?
These 3x3 10W things seem to be happy at 3 amps/~11.5v (using ebay adjustable DC-DC converter as a driver). It's a shame they only got measured here at a measly 1A. :p
Interesting Comparison
Nope. I was thinking of a car DC alternator for the above part, but in case of lawnmower, yes, a different set of variables need to be used. Probably if the input is too high against the Vf, the resistor is not a viable option due to high loss.
Didn’t know about the Vf being 9.6V (what’s the I-f at this point?). Also, the fact that the current reaches 3A at 11.5V as comfychair mentioned - really didn’t expect that!
Anyhow, I ordered a couple of sets anyway, both WW and White (real users reported this to be actual 5000k temp instead of 6000k on spec, which is practically NW), will try to experiment with them.