KDIY KF8 flashlight (1x18650 XHP50.2)

I have both OP and SMO on hand.

Also ordered the H2-C driver to play with. Will see what both drivers can do with resistor mods. My guess is they will probably be thermally limited unless they can transfer heat to the host, and getting much more than the stock 18W will be hard. Still nice to see some good boost drivers coming out. Now we just need more quality hosts with stock 20mm+ drivers.

Back to the KF8 though. I have a Roxane M6 with a very similar switch arrangement. Same orange Omten with the ring and pad contacts. Never liked that design much, especially if there is room for a proper PCB switch.

I may go for the standard switch at some point, the brass switch container can be the source of a retaining ring by sawing a piece off, and just the height of the assembly must be guarded.

An extra piece of information on the driver:
I ran the battery down to 3.50V resting voltage, so well over half-drain, and measured current and output at 30 seconds. Current has increased to 5.6A now, and output is 1905 lumen. So the driver is still totally in control of the output! :sunglasses: Mind however that I did remove some resistances in the light, so the stock light may not get this result.

I found an extra negative for this light: when the switch assembly is screwed really tight, the way I like it, the battery tube does not make electrical contact with the tail (a common fault with these tail designs). So it needs the paperclip treatment :frowning: (I used a stripped and bend piece of 20AWG wire filled with solder instead).

The Thorfire C8s uses a 19,6mm driver very easy to fit the H1-A driver :


Great review.

Every so often, I read that the big explosion in flashlight technology has already tailed off. The biggest jumps in output came at the beginning of the LED revolution, when flashlights went from somewhere around 80-100 lumens up to about 500, and soon thereafter, to 700 or 800.

I gotta say, I just don't buy it.

When you can get a 2000-lumen light like this for only $35 USD, I say the game is still on!

Hi djozz, thanks for the great review! I have been eyeing this light for quite a while already and glad to know that it performs pretty well. :slight_smile:

Did you try to stack an R100 resistor and see how much output it can give?

Edit: Jensen has tried it here and the results look promising. Adding an R100 seems to have pushed the driver to its limit already tho.

No, I did not do the R100-mod yet. I may first wait for a good highCRI XHP50.2 to become available before I start modding this light :slight_smile:

Yeah that’s good too. I am not sure if these newer XHP50.2 tint is really bad or not, haven’t seen one by myself yet. So in your opinion is the tint really bad?

Thanks for the review djozz. Looks like a nice flashlight. I read on the Kaidomain website that it has a “Low Voltage Warning: It will keep flashing when the voltage is below 3V.” Do you know if it eventually turns off, or does it just keep flashing?

I’m just not too fond of cooler low CRI tints, and in combination with a less than perfect beam and some tint-shift over the beam makes this light not my favorite. But in a 90CRI 4000K tint it get ways more attractive. Let’s see if that will become available somewhere, I hope for KD.

Thanks for the review Jos.
Hmmm, looks better than the Haikelite I planned to buy (sold out already). I’m getting more into boost driven FL now for their flatter runtime. The Haikelite MT01 wins in battery capacity while KF8 is more EDC-able.
Can you please measure the reflector largest width and height for me? If my Gaggione TIR fits in, then this could be my next toy.

- Clemence

I will do reflector measurements and check low voltage behaviour when I’m home again, perhaps I have time on monday.

:+1: :slight_smile:

The regulation seems very good, should be even better at lower current. I’m not a big fan of brute 2000+ lumens. A well distributed 1000 lumens (purpose specific) is more than enough for outdoor uses while 300ish lumens is the most useful max for daily uses… Wondering how efficient this boost driver really is. Let’s hope it’s higher than 88%

- Clemence

My testing has showed over 90% efficiency for the stock levels, starts to drop off as more current is demanded with a resistor mod though. Check out the numbers here.

Very nice! The stock level is more than enough for my liking. Too bad it cannot drive more than 7V reliably. This is a better option than the expensive Taskled Luxdrive for 6V LED applications.

- Clemence

Well at some point I want to pull the inductor and try to reverse engineer the board. If it is indeed the TPS61088 we should be able to bump the output up to 9V+ for a triple.

That said, even stock it is a fantastic driver for 6V LEDs, especially for the price.

I will probably get either this KF8 host or the 26650 K5 host.

Still comparing….The K5 has better runtime but the strike bezel won’t be good for my jacket pocket. The KF8 SS bezel is also stronger.

Has anyone got a reading for candela for these?

Being an XHP50.2, smallish sized and orange peel reflector, the number won’t be spectacular. This is an all around general use FL I guess. But very potential for some eco builds

Agree clemence - just nice to have an idea of the throw. I use my c8 and maxtoch 2X hunting and this would fill a gap for a general torch that if able could be used for some short range work

Would it be 30kcd?