Zooming C8 Host with De-domed XP-G2 - Complete with average beamshots

Well it is up an running. The beam is very tight, works well but not quite as powerful as I thought it might be. However this one was really just a practice for me and the host is certainly not that great and the optics even worse. I will look at a better host with some better optics and use my other driver I have here and the XP-G2 on the Noctigon.

Checked the tailcap current and it is doing about 1.78A and I was expecting 1.75A so its all working correctly. This host really is not adequate to run it at 3A plus I am only using the cheap XP-G2 from FT which is on a thin aluminium MCPCB.

Excuse my poor camera skills. These are the first beamshots I have ever done.





Hey LSX that beam looks pretty tight to me, I’m a thrower addict, so it looks ‘da bomb’!

Just outta ignorance AND curiosity, what did the extra 7135 chips do exactly?


The host needed a 20mm diameter driver which is hard to find in less than 3A. So I bought a 20mm one from IOS which was only 1.05A. An XP-G2 is “recommended” to be driven no harder than 1.5A and since this host doesn’t have very good heatsinking I didn’t want to overdrive it much past this. Piggybacking the 7135 chips increases the current output from the driver. Each one adds 350mA (I think 380mA ones are available as well). Hence, my original driver is now running at ~1.75A with the addition of two 7135 chips.

Ahhh, I see!

So why not direct drive it?

I think it will get too much current and overheat. However I am not quite sure how the current draw works on direct drive.

I have a Jacob A60, and 2 ‘zoomies’ on direct drive, I’m using sh*t 18650 batteries though, the red ones, and it made a hell of a difference to the Jacob, and I put XP-G2’s in the zoomies, what a difference!

I purchase a torch from a supermarket here….Asda, a Status 3w led one, utter crap for £8, I was lucky as the packaging was wrecked on mine :wink: , I got it for £4.

I de-soldered the cheapest lookind star I’ve ever seen, and put an XP-G2 on there, the torch was direct drive anyways, I had to sand the base of the plastic reflector down to let the led sit right, it’s now a really good but floody thrower. I sense it’s gonna get dedomed!!!


PS: that IS a really tidy solder job, is your soldering iron a fine tipped one?

The current it'll run at depends on how high the cell can keep the voltage, lower voltage under load will cause the LED to flow less current. Higher voltage will allow more current. If you were to power it with a theoretically infinite amperage source, but limit the voltage to 3.2v, it'll never pass more than 1.6A.

I am using a Panasonic NCR18650B 3400mAh protected cell. How much current would it draw off that battery fresh of the charger (4.2v)

Hey Comfy,

So would using sh*tty so called Ultrafire 18650’s (i can tell they’re not original, as the writing on the side mentions ‘sheef life’ as oppose to shelf life, check yours if you have em) minimise any risk of the emitter burning out?


Cheers, I use a Snap On YAS32A which is a butane powered iron, adjustable from 25w to 125w and I use the 1mm double flat tip.

Cheap sh*t then?

hahaha something like that.

Figures…… :Sp

If you want more performance forget the 7135’s. All you’re doing there is losing output thru heat and multiple added connections at the driver side instead of letting the emitter lose it instead in shear brightness to whatever that particular emitter is capable of putting out. And every emitter to boot is different. XPG2 can handle more current than you’d think assuming there’s an decently adequate thermal loss path under the star. If an Xpg2 can handle a 26650 direct drive fully charged it’ll handle most 18650’s too unless maybe if you’re talking an A123 or something.

Let the dog run! lol

Oh and LSK, when you say ‘zooming’ host, what is the hotspot like?

Is it the square variety?


So how do you go about direct driving the emitter?

It’s round when on full flood but when zoomed in it projects a perfect image of the emitter. Although the focal point isn’t very good and at that point it has lost brightness.

I used a 20.4mm contact board from intl outdoor, +ve wire in the middle -ve wire to the edge, solder on a spring, attach to star, lash on some thermal greasy stuff….you have a single mode superbright torch!

Read this mate

From what I gather, the loss is down to the crap optics, direct drive it, better optics, and guide the planes in!!!