Upgrade options for more lumen single cell

I have a C8 with Xpl hi and a 7135x12 driver. The light is awesome but thought it be interesting to see what else I could do to the same host without with minor changes.

Any ideas or advice to increase lumens? Not substantial but significant enough. I have some new high drain 18650’s that maybe could come into play.

I thought about a Fet driver but… would that make much a difference? I would think if I used Fet I’d likely need to use a cell thats not rated over 10 amps or so. I have some new 25R and a P26A 35a cell that I suppose would be a bad idea if I kept same emitter. I’m not sure how hard I can push the Xpl hi.

I’m doing some research and schooling myself on forward voltage and so on but it’s going to take a little more studying to fully wrap my head around it all.

I’m basically seeing what’s out there without using a 6v emitter or 3v triples.

BTW, I have a XM L2 as well. Not sure it that would work better.

I had asked this question several months ago but was mixed with another topic so I didn’t really nail down a good direction. Thanks

There are options for you out there. Your C8 with 12-7135’s is about as bright as that XM L2 is going to get. Take a look at your skill sets and if you’re up to it you can change out the LED for some brighter ones;XP L2, XHP50.2, Samsung LH351D, SST40. intl-outdoor.com is a good source of LED’s. You’ll need to research your driver just too many to list but Convoy is a good place to start. I’m guessing your light uses a 20mm LED MCPCB and a 17mm driver. I’d expect a good max current of 6-8 amps. Take a look at spring bypasses, thicker wires, etc. I wouldn’t do a Fet driver without a thermal sensor.

Changing out the led wouldn’t be a problem. I’m running 22awg wires and both springs are bypassed.

So your saying an XP L2 would be brighter than my current XPL Hi using the same 7135x12 driver?

*Edit: I guess it would be a small difference because xp L2 appears to have more forward voltage. The 6-8 amp you mentioned for my particular light would be perfect. I’d definitely have to change something with the driver though. My 7135x12 is rated around 4.5 amp and that’s exactly what I show at the tail with the xpl hi emitter.

Is there any benefit to using a very low IR cell when it comes to using drivers with 7135’s and emitters like Xm L2 or xpl hi? I know there’s less voltage sag but is the higher voltage under load even usable with these LEDs?

The C8 can handle a lot of power, I tried xpl HI, xml2 and others, the real change came with the XHP50.2 3V and a different driver. With a weaker cell and no bypasses, my FET driver works fine. But if I ever decide to bypass all springs and put a stronger cell in, it might be too much current.

So you could change the LED, put in a stronger driver and limit the current with the bypasses or the cell you use.
Lots of options to play with, either way the C8 is a great flashlight.

The XPL hi V3 is about 10% less output than the XPL L2 hd V6. The XPL also has a higher forward voltage than the XPL L2 that could actually limit your current. Hi amp cells won’t be needed here, go with hi capacity 10-15 amp cells. This Cree table may help a bit https://cree-led.com/support/tools

That higher voltage serves a vital purpose, it’s what helps over come all the other resistance. Volts/resistance=current. Save those 35 amp cells for 20 amp lights. 10-15 amp cells are about perfect for 6-8 amp loads, cell has plenty of extra not to be stressed.