I purchased this driver for a 14500 project to power a single 219B.
Would it work, or is the 100% mode too much power for the emitter.
It is not recommended, you might fry the 219b
Damm, guess I need what? a LH351B or an SST20 to handle that?
They list quite a few options for firmware and for turbo mode timer settings.
You would need to get the datasheet for the battery cell to see what are the voltage and current ratings, then decide how you want to operate it. e.g. 100 % full power, max current, or something more sensible. 80 or 90% of max ratings to maintain some margin.
Then look at the 219B datasheet to see the maximum ratings and make the same decision,
then look at the various firmware and turbo timer versions to see which one is suitable for your project and allows you regulate and control to fit within your performance envelope.
I got standard firmware with memory Moonlight - 2% - 5% - 20% - 50% - 100%
Just figured since it was a 14500 it wouldn’t hit it so hard because it had less amps.
You’d want to use a low current cell and maybe some thin wires to the LED, and your 219B should be on a copper DTP star. I think you’d be ok. If you kill it, you could always swap to a 219C or whatever.
Output test for 219B. Nichia 219B 4500k D220 9080 CRI Emitter output test by Texas_Ace; Amazing tint and CRI! Output is what you would expect.
Looks like around 3 amps is the sweet spot with good heatsinking.
The driver linked is almost the same as direct drive in high, being that the driver will allow what ever current to voltage ratio the battery can deliver vs led vf.
Given that the led only needs 3.23 volts to push 3 amps at its sweet spot anything above that is waste or going to kill the led.
Most batteries in the 14500 (assuming that’s what you meant by 15400) size will give more than 3.23 volts at 3 amps.
With a poor quality or low current 14500 cell it could work. But for most cells nowadays I would assume it may let out the magic smoke.
Just my two cents. 
Yep, as Hoop mentioned there are other ways to limit current: thinner wires than normal, low current cell, you can also programming the driver to a lower power level, 50% FET for example. Or you can try a combination.
Thanks for all the advice guys! I think I’ll forgo the 219B and use a 219C or LH351 because you can push that way harder.
There is also the Luminus SST20w FA3 and Nichia 519AT to keep in mind
I use 5 amp driver to power a 219b. Only get about 3.5 amps using old laptop battery, so they run on direct drive basically. You must check max current. Or just measure ceiling bounce brightness at all levels. 219b tops out at 4 amps. I imagine that 50% and 100% will be indistinguishable.
Lots of good advice above. Now, not all 14500’s are created equally. I have several that put out 6+ amps, but the higher capacity cells are more in the range of 3 to 3.5 amps and slip quickly after that.