Got a C8 XPL Hi from Gearbest
As I did a spring bypass I noticed a plastic spacer as well but it was looking good
I got a brand new shiny Clear ano C8 in the mail yesterday. 
I stuck a protected EVVA cell in it and tested it…
0.01A for 3.07 lumens
0.08A for 28.29
0.41A for 135.24
1.24A for 432.63
2.70A for 917.7
This is completely stock with 8 of the 350mA 7135 chips on the driver and 28 ga leads.
So, today, having allowed a full 24 hours to pass (I know, right?) I tweaked the shiny little devil.
I pulled the driver and re-flashed the Bistro-Mini firmware from the original that TK sent me when all this was first getting going. Then I stacked 6 350mA 7135 chips, swapped the 28ga leads for 20ga leads, put a new XP-L W2 2B on a 20mm Noctigon and shaved the centering ring to about half the base thickness.
Now, it’s a pretty sweet light!
0.02A for 4.07 lumens
0.14A for 50.13
0.70A for 244.95
2.21A for 724.5
4.84A for 1511.1
Wonderful! Thanks for the great work Simon, Jared and TK! Just gotta love these little C8’s for what they can do and how easy it is to mod one.
Plastic spacer in the tail switch? Oh the outrage! (preparations being made for a lighted tail cap, hence the clear boot, shhhhhhh!)
I plan on adding one of those nifty 6 LED tailcap boards for my clear C8 when I work up the courage to solder those tiny boogers. I went ahead and bypassed both springs and put in a FET +1 along with an XPL-HI V2-3B on noctigon. 108kcd before tweaking focus, haven’t measured lumens or tailcap amps yet.
Damn, that’s hardly any drop in efficacy from 2A to almost 5A!
I gotta get me some DTPs…
I’m seeing 5.8A at the tail with my clamp meter.
Freshly charged 4.201v 30Q measures 111kcd and 1508lm at 30seconds.
FET +1, XPL-HI V2-3B on noctigon.
Is that a fairly low throw for this setup? I imagine I need to tweak the height of the centering ring right?
Try taping off the base of the reflector with kapton tape and doing away with the centering ring, see if that nets you any gain. The HI can be pretty fickle to get it just right. Sanding down the centering ring or removing it altogether is likely to give a better focus, it’s a hit and miss kind of deal.
I switched to the new XP-L W2 2B and actually lost throw numbers, sanded the centering ring down to about half it’s base thickness. But I like the beam profile so I’m not worried about the numbers.
I think it’s nearly max with xp-l hi .
Fet driver and :
Xp-l hi 105-110kcd
Xp-l dedomed 145-155kcd
Xp-g2 old dedomed 165 up to 195kcd
That’s unfortunate. A simple accident no doubt but still a bummer. I passed the info and pictures along to Simon. If you contact him through the Ali message system he will certainly make it right. These type of things will come up from time to time but Simon always takes care of any mistakes like this.
Hello all,
This is an excellent thread and I thought it best to post here where the expertise is rather than clog up the forum with yet another thread. I’ve read though this thread and my problem doesn’t seem to have cropped up before.
Yesterday I received an updated C8, the XPL HI model this thread is about. I put a fully charged NCR18650B in it and switched it on, cycled though the modes and was generally very impressed. So far, so good.
The issue was when I attempted to put it in config mode to change the settings. I clicked it on, and then proceeded to tap it quickly but steadily expecting it to stop turning on and then buzz. Problem is, it didn’t seem to go into the config mode. Confused, I clicked it off and clicked back on again, it came on low (0.1? 1?) and then no matter how many times I tapped the switch, clicked the switch or anything else it refused to do anything other than this low output.
In summary, after attempting to go into config mode and failing I have been left with a light that switches on with a very low output but then refuses to do anything else no matter what.
Has anyone else had this problem or even have any idea what might be wrong? Is there a way of doing a ‘hard reset’ back to the default settings?
I thought I’d post on here before taking it up with Simon at Ali, from what I hear in this thread he seems to be a busy man and I’d rather not bother him if I can sort it out myself.
Many many thanks.
Hi Alex, welcome to BLF! 
These drivers with new firmware, that are used for the first time in the clear C8, do have a programming error that as far as reported yet have no serious effect on the actual functioning of the flashlight. But you may have encountered a problem after all.
Personally I have tried this same driver (I ordered them as bare driver from Simon) in a triple XP-G3 flashlight (S2+ shorty with 18500 cell) and it acted weird too (but different: overly enthousiastic stepdowns, seemed to switch on in a random setting). Perhaps my use was a kind of out-of-spec use, so I will not blame the firmware for that.
Maybe others have encountered problems too and care to report here?
TK said that a programming error by the factory caused the drivers to run at twice the speed they are supposed to, effectively overclocking them. This can lead to odd issues if it is widespread. I never saw a conclusion to that issue although it should be a simple fix ones figured out and not effect the vast majority of users.
I flashed this new biscotti to 3 lights. one of them is normal speed and two is twice as normal.
Are you thinking the new firmware was responsible for making the MCU run at double speed?
The technical side of creating firmware is beyond my understanding, but I suppose it’s possible.
I’m sure ToyKeeper is on the case. I think we are all just waiting for an official reply from her or Simon (through J-Dub74).
She said in a prior post that it was the new firmware that was the problem. It worked fine with the 5 old drivers that I flashed (105C and 105D).
Oh, was it in this thread she said that, because I don’t see it here.
Well, I guess that answers that. Lol
I thought I remembered it being fuse* settings that caused the speed issues. Not certain though, might be more info in the firmware thread. Might help to take some of these questions there.
*Fuses are settings that you specify when flashing firmware to a chip. So not really the firmware nor the hardware.
Could someone send me the chip on the drivers programmed with biscotti firmware?
Correct, most do not understand that though so I just used the word firmware.
Thank you :+1:
It seems like it might be an exceptional case, I think I will contact Simon and see what advice he gives and whether he wants me to send the light back so he can see what’s up. I’ll keep an eye on this thread though for any updates.