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

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.

Generally, yes.

Turbo is not a specific number of lumens; it is direct drive. Brightness is determined by where the LED’s forward voltage curve meets the battery’s discharge curve. And, at only 2.9V, it won’t be very bright no matter what kind of battery is used. That is an empty battery pushing less voltage than the emitter wants.

According to Texas_Ace’s testing, it would max out at less than 230 lumens per emitter at 2.9V, even if the battery was capable of pushing a thousand Amps.

This is the answer i’m looking for, thanks a bunch.
Don’t know why i keep saying turbo, it’s a habbit i guess. But yeah, i was wondering the emitting capable of the LED at low U and high I :smiley:

Something I was wondering if this would work.

BLF Q8 with NarsilM v1.0 (or v1.2) doesn’t have thermal calibration feature.

Let’s say the stock BLF Q8 (or other NarsilM flashlight for that matter) is very wrong (eg. ambient is 25 deg C, but “thermal check” reads 45 deg C)
Say I flash it to Anduril, then I calibrate the temperature there (25 deg C more or less is 25 deg C)
When I flash the Q8 back to NarsilM (say v1.2), will the thermal sensor (which was previously calibrated when it had Anduril) be back to the earlier wrong reading, or will it become correct (the value configured in Anduril), or just some other random thermal value?

HKJ and Mooch both put constant loads on the batteries starting at 4.2v and ending at 2.8v and discharge it at multiple rates. To get a continuous rating the cell has to stay within a “safe” temperature range. I think this is below 80°C.

It can be a bit off. It just means the light might thermally stepdown too early or too late. Usually the factory setting is pretty close. You can customize the step down temp to whatever you want or switch to a timed stepdown.

When setting the thermal step down temperature yourself, the light will turn on to turbo and then you just hold the light until you think it’s hot enough and then click the button. So you don’t actually have to know an exact temperature number to set it. Whatever temperature number it read when you set the limit is when it will step down in the future.

The temperature sensor is built into the MCU chip and you can’t really get super accurate reading from this style of sensor compared to an externally mounted sensor. It still works fine, though. You don’t even have to have a thermal step down if you don’t want it. You can turn it off and then control the temperature manually like most lights.

Yes, it will return to its original wrong reading.

I think I can answer this.

I believe the way Anduril calibrates it’s sensor is to just adjust using a correction factor meaning it adds or subtracts a certain amount from its reading. So if the light is actually 25°C and it’s thermometer says 45°C (the tolerance would not be that high, maybe plus or minus 10°C is more accurate) then you would tell it to subtract 20° from all its temp readings. Now it’s “accurate”.

If you flash to NarsilM, that correction factor disappears along with all the Anduril code. So it should be back to reading 45°C.

As it was said earlier, the MCU does not really need to know the accurate temperature. It just needs to know the relative temperature so that it can activate the thermal step down.

I’m not sure why ToyKeeper added a temperature calibration circuit, since it’s technically not needed. Maybe there’s something specific to Anduril that needs to know the actual temperature?

Because you click however many degrees above 30C you want it to step down at. 60C = click 30 times. So now you have a calibrated temp and a more precise step down setting.

Is this in reference to me asking why Toykeeper added the temperature calibration?

Why do you need precision? My hands tell me when it is hot enough. The thermal step-downs main purpose is just to prevent you from burning your hands. Eh, no big deal.

Why not? Why do people like Android phones over Apple and vice versa? With a value I can (easily) tweak it a little higher or lower as I wish. They both get the job done.

I like the simplicity of hold-until-hot, but in this case I went for something a little more complicated in order to get better results.

Running a light in turbo until it feels hot enough… is kind of obnoxious and imprecise and not feasible at a factory… especially on bigger lights where it takes a long time to heat up.

The calibration function makes it much easier to get consistent behavior on each light. In theory, the company making or selling it could calibrate each unit in about 30 to 45 seconds, and avoid a lot of issues with products overheating.

If it’s not factory-calibrated though, it’s still reasonably simple for a user to do it, and faster than the hold-until-hot method. Go to thermal config mode, click enough times to tell it the current temperature, then wait a few seconds for it to fall out and go back to its previous state.

Anyway, hopefully the factory or vendor will do it so the user doesn’t have to.

Ah, fast factory calibration. That makes sense. Do you think Lumintop will try to calibrate all the FW3A lights?

I don’t know, but I hope so. I recommend it, repeatedly, to everyone who sells lights with Anduril (or RampingIOS V3, which also supports calibration). It improves things for users, and should reduce return rates for vendors, by preventing common issues.