Me Too! I emailed Hank the min I saw this but my order had already shipped . Now I’m thinking about selling something to justify another light.
One possible explanation is the SST-20's draw lower voltage, so for a higher qty of LED's on just one single cell, the lower voltage LED's should result in drawing even higher amps per LED. 4 to 8 LED's may result in jumping over the threshold of giving the 5000K SST-20's the advantage.
SST-20 is also more efficient at moderate currents but less efficient at higher.
They pretty much all are, so as you increase LED count off a single cell, efficiency goes up and amps/LED goes down because of increasing batt resistance, LED wire resistance if still using one pair of wires, etc. But then again you got all that heat concentrated...
with all this 8 led mule talk… how long can it run at max?
I love the one trick stuff but I am getting more and more into sustainable high output…
I’m not talking about the change of efficiency but the change of relative efficiency.
At low-medium current SST-20 is more efficient than XP-L HI. At high current XP-L HI is more efficient than SST-20.
Perhaps like .. 5 seconds?
I would have thought 2 secs max. My D4V2 drops like a rock at turn on.
My D4v2 can maintain even 30seconds of turbo on fresh 30Q, there is no dropping like a rocket.
I'm fairly sure that it doesn't (I have a D4V2 too). You might not see the change with your eyes though, e.g. 3000 and 1500 lumens looks pretty much the same esp. if you just looked at 3000 lumens.
My D4 drops within 7 seconds, but that’s because I put quad Luxeon V in it… 5000 lumens at start-up is spectacular though!
I should check it out with the meter, how much it actually drops and how fast.
However “dropping like a rocket” means dropping clearly visible to me. Can something dropping like a rocket mean something subtle?
My XPL-HI 5D stays on turbo with fresh batteries for easily over 30 seconds…
I found similar results when comparing XP-G2 to XP-L HI in the original D4. In a quad, XP-G2 made more lumens per Amp when the total output was about 3000 lm or below, while XP-L HI made more lumens per Amp at about 3000 lm and above.
I’m guessing a similar effect shows up when comparing 4x to 8x, since the total power per LED is lower. Instead of 5A each (20A/4), it might be 3.75A each (30A/8), or something along those lines. This would give more of an advantage to LEDs which are relatively more efficient at lower power levels.
Also, LEDs with lower Vf tend to perform better when a bunch are used with a single battery, because lower Vf allows the battery to push out more power. It might be 30A for XP-L and 35A for SST-20, due to differences in voltage.
About how fast it drops from turbo, a lot of that depends on the temperature the light started at, the type and condition of the battery, the LED type, the ambient temperature, and even how clean the electrical contacts are. Also depends on the firmware version and the thermal configuration.
When used at approximately room temperature though, the overall time for a light the size of a D4 or KR4 to reach a sustainable brightness can be from about 10 to 60 seconds after a cold start from turbo.
I think the elements in the time of direct exit are of great importance. If D4 consumes more than 17A in Turbo from VTC5 or 6, then I do not think that Q30 can provide this. Especially considering the issue of originality of batteries from China.
I.e; not being able to give a high current and drawdown of an element for voltage increases the Turbo time. Of course with a lower lumen output …
Can the tritium tailcaps be purchased seperately if we have already ordered and the light has shipped?
+1
I ordered a “yellow” tritium button and tried adding a non-tritium cap to my order but Hank said he was not selling them separate. Perhaps not enough spares?
Is the D4V2 mule version equipped with the driver from the KR4 (regulated up to 5A) or with the D4V2 driver?
Sorry for my bad english, it’s my second language
regards,