(BLF) Sofirn Q8 V1.5: The XPL HI monster, DIY parts + Extended 8x18650 tubes GB Interest List

Sofirn is the company who made the Q8 for Thorfire. I don’t know if they will source new covers. They probably have hundreds of the T logo covers and will just continue using them. Maybe they will comment on it. It makes no difference to me.

Love the options that Sofirn is bringing to the table, some excellent and some not such great ideas. Well, Sofirn’s ideas appear sound but the ideas of going for 20,000 lumens in this light are sure to get someone in a bind somewhere. Insufficient cooling. Take it from someone who knows… :wink:

I wonder if they tweaked/updated the NarsilM v1.0 of the BLF Q8 for the new Sofirn Q8 with XPL-Hi (eg. using NarsilM v1.2 would make it better, adding momentary tactical and also strobe modes get accessed better).

Would there be a big enough different for XPL-HD to XPL-Hi in terms of the heat management features or other features of the previous BLF Q8 NarsilM? And also wondering, if the Anduril for BLF Q8 will also work on the Sofirn Q8 (assuming they used the same MCPCB and only the LED changed and minor stuff)

Yes, the regular Sofirn Q8 will use NarsilM v1.2. I don’t know about the v1.5 that this thread is focused on. You can find the Group Buy here.

Heat related stuff is the same.

It should be the same driver so Anduril will work.

T stands for nothing but for better finger touching. It could be many dots or other designs but we already have this. We might use new design of the cap if there is good new idea.

Do you have any ideas?

I assumed “T” was for Thorfire. If you did order new ones, maybe use a “S” for Sofirn. IDK, it’s not a big deal. Maybe even a blank cover.

I’d say don’t waste time or money on new caps. Use up what you’ve got. It doesn’t change the functionality of the light. :wink:

I want a seperate battery tube that use 3*26650 or 3*21700, or some big boys like that. That way i can have longgggg run time thanks to the bigger cells. And when needed i can switch to the conventional 18650 tube again with no hassle. What do you think? :face_with_monocle:

3 x 26650 5700mah = 17100mah
3 x 21700 5000mah = 15000mah
4 x 18650 3500mah = 14000mah

There’s not a big difference. If using the 26650 Shockli 5500 or Keeppower 6000 (both are about 5700mah) then you get a 22% increase in capacity. That would help a little, but not a whole lot.

And unless you run it down to vapors anyway, it’s not going to be terribly noticeable.

Will it be possible to buy the 2 new tubes (with battery carrier)? And will it work with the original Q8 driver?

Aye, but i’m using only 3000mAh cells. Beside when the voltage drop (say after 40mins-1h)so does the light. I’m hoping the 26650 can retain the high output a little longer? I have little experience with these cell honestly, just looking for a reason to try them out :stuck_out_tongue:

@TheOnlyDocc, yes it will be possible to buy the whole carrier array separately.

And yes, it will work with the original driver since the carriers are all in parallel.

Here is a generalized and simplified chart to show different battery combo’s.

CDR = continous discharge rate. (Best cells tested by HKJ)

3 × 26650 5700mah 20A CDR = 60A CDR 17100mah
3 × 21700 5000mah 10A CDR = 30A CDR 15000mah
3 x 21700 4000mah 20A CDR = 60A CDR 12000mah
3 x 21700 3000mah 30A CDR = 90A CDR 9000mah
4 × 18650 3500mah 10A CDR = 40A CDR 14000mah
4 x 18650 3000mah 15A CDR = 60A CDR 12000mah
4 x 18650 2500mah 20A CDR = 80A CDR 10000mah

You can see that the 26650 has the highest combination of capacity and amperage. This is because it’s the biggest physical battery. It’s double the physical size of an 18650 and the 21700 is in the middle at 50% bigger than an 18650.

The problem here is 3 x 26650 is too big a diameter to fit in the Q8 battery tube.

4 x 18650 can fit in a 44mm circle
3 x 21700 can fit in a 46mm circle
3 x 26650 needs a 57mm circle

Also keep in mind that you don’t need crazy amperage for the Q8. Typical is 15A with maybe 20A the max. So let’s look at the loads of each cell at 5A.

So if you want the longest run time at high outputs, not considering heat, then the middle of the road 18650 3000mah and 21700 4000mah is your best bet. Both give you the same 12000mah capacity. So there’s no real benefit switching to 3 x 21700.

If you want the longest run time at low levels, then the high capacity 18650 3500mah and 21700 5000mah are you best bet. These have an advantage at the lower voltage levels between 2.8v to 3.2v to give extra run time. Switching from 4 x 18650 to 3 x 21700 only gives you a 7% increase in capacity, though.

The best of both worlds would be a bigger battery tube to fit 3 x 26650, but I don’t see that happening.

Is the CDR number indicate discharge rate at all time, like until the battery is nearly depleted or it’s just the average rate? I like to be able to hit turbo even with low battery if that’s possible. I also hear with enough current you can boost the brightness off the chart up to nearly 7000lm, that i’m a bit ambitious with.
On the side note: Are there any way for the user to calibrate the temperature sensor of the light? It kinda pointless having a thermometter that isn’t accurate isn’t it?

On these lights “turbo” is just “as much as the battery can supply to the LED” - you will always be able to get to turbo but it will drop in brightness relative to your battery voltage/current for the entire time you have it on. So turbo at 25% battery will be quite a bit less than turbo @ 100% battery. There are more advanced lights and boost drivers that will give a more constant current despite battery level but they are quite a bit more expensive (ex: Noctigon Meteor M43)

It isnt pointless to have to temperature set wrong. Depending on the firmware some will allow you to set the step down in two ways:

1) in config mode there is a way to get it to go in Turbo and you hold it there until you think the light should step down. It sets the ceiling. This is a relative temperature and as long as it’s consistent it’s very much still worth it.

2) Some of ToyKeeper’s newer firmware will let you program in the ambient temperature and then you choose a step down based on a temperature value you choose

With the right firmware, yes. Anduril has a thermal calibration / configuration mode.

I wonder if the maximum brightness of the light from 18650 at 2.9v and 26650 at 2.9v are equal.

LED current split across 3 cells will be more critical as far as springs, bypasses, etc., vs across 4 cells.