I just tried to enter from my phone and it worked (I thought I tried from my phone, weird).
Ok, the issue is with my PC then, the old bastard.
Thanks everyone.
Is it possible the T6 is boosting the voltage using a 14500 cell? The output measures higher compared to using a 17mm 5A Buck with SFT25R. Using the T6 I’m getting over 1500, with a C8+ 5A Buck it’s around 1350, an 8A Buck is 1500 - 1600. There’s no chance a Vapcell H10 button top is holding a higher voltage vs a Molicel P30B.
I’d love it if Simon could produce an 8A boost driver for the SFT25R, that would be amazing to get 2000 lumens out of it.
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Doesn’t a boost driver increase voltage? Wouldn’t you use a buck for a 3v LED?
Forgive my lack of knowledge if I’m missing something.
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That actually may be possible because T6 driver is boost+buck, where boost should be for AA. What if you try to connect two low Vf LHP531 in series, will it boost the voltage to around 5V?
Well, that’s interesting. I added copper braid to the negative ring of the driver extending outwards, I wanted to make sure the retaining ring was making good contact. Now instead of around 1,450 at 30 sec, it’s 1,687 with over 1,800 at turn on. The 17mm 8A Buck driver is too small for the retaining ring it seems.
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Yes, that’s right, but a boost driver can be used with 3V emitters. The new Wurkkos TD11 uses 2x SFT25R’s with a boost driver, it reaches the 3,000 lumen spec even at 10% charge.
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May be some issue causing the 8A buck drive to not output the power it should. The actual output power of Convoy drives does not always conform to spec.
I was thinking if it’s worth it. Looks to me that 25% increase in lumens (which probably means around 10% increase of perceived brightness) would cost some 80% of increased power draw (@koef3 SFT25R test), increasing heating rate and shortening 100%/Turbo runtime.
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I’m not too interested now after finding out the cause of the low output. Poor contact of the retaining ring on the C8+. Output reads 1,482 at turn on and 1,402 at 30 sec before the mod, now 1,837 and 1,687.
Edit: tried it on the L21B with no gain, so that’s not the cause on the 22mm 8A.
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Does your C8+ have the standard retaining ring or the thinner one?
Can the driver shift around inside before you add the retaining ring?
If so what is the diameter of the 8A driver?
Well, scratch that.
My previous 15x C8+ that arrived with the wrong driver, had solder blobs to connect with the retaining ring, Simon sent replacement drivers that I fitted. For some odd reason the contact is poor and requires the added solder or copper braid. The retaining ring is standard and the drivers are 16.9mm.
The 15x C8+ that arrived on Friday connect just fine and give a measurement of over 1,900 lumens at turn on.
Then in my earlier C8+ it measures just over 1500 at turn on.
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Soooooo, there’s either been a new driver batch or better LED bin recently. All new C8+ and L21B stock measure 1850 - 1900+ at turn on. Earlier stock tested 1400 - 1500. That’s great news, no mods needed.
Edit: Swapped in an old 22mm 8A Buck to see the same higher output, so that points to a higher LED bin.
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Is this SFT25R? Is the higher output observed with the 6500K or 5000K? I might want to order some if the performance has changed substantially.
It might be a higher flux bin, or a lower Vf bin.
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SFT25R 5000K. Haven’t bothered with the 6500K since the 5K achieves the same output, at least in the old stock.
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Thanks for the info–much appreciated!
Do you happen to have a device that can measure current at the battery? This might clarify whether the increased output is from higher flux bin (i.e., higher efficacy), or from lower Vf that allows the LED to draw more power. The old SFT25R had lots of trouble reaching 8A from the 8A buck driver, even on a full cell.
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@Simon_Mao just saw that you have a new 3V 20a buck driver in production. Can you please give more details such as:
• what is the UI? Anduril?
• when is the M21k coming out?
• when is the driver expected to be available?
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Uh, the M21K will finally be a real thing? 
So nice, I have finally run out of Convoy lamps to buy, I already have all that I ever wanted.
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Who knows? That was a question, not a statement.
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Considering the page lists the new driver as compatible with M21K, I would consider it officially announced at this point.
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LHP73B got added to the 4x18a but strangly not to any of the 3x21 lights 
interesting. Why can’t the 3v 18a 4x18a driver fit in any of the other lights?