Mmm, the standard 4 modes ∅17mm 5A driver is close, but I guess close is not enough, namely because of the low to high mode order. It's maximum driving current, being slightly below 5A, is spot on for the fashionable CSLNM1.TG, though.

I understand the preferences thing, I know how the mind works and when one believes something could happen, it's only a matter of time for it to happen. Thus, to completely preclude driver misconfiguration wise or pragmatic man sticks to unmessable driver. :-D

Does the lower VF bins for Osram KW LEDs mean longer runtime on battery ?

This statement is too vague to answer as is. A buck or boost driver may benefit from low vF while a linear driver may have no impact or slightly worse and a FET driver may be worse still (as far as runtime).

“Efficiency” is in the datasheet for each brightness bin but it all depends on how you power it.

I see, so this cant be stated until you know your flashlight setup, specially with driving these LEDs way above the default current.

Right, usually you will pick two and figure out how to make the 3rd work with your first two choices: LED, Host, Driver

We only have so many resources after all.

First of all, if you need to measure runtime you must provide a clearer definition of runtime. I understand it basically can be defined as “the amount of time the flashlight remains powered from switch on until condition”, thus you need to define condition for runtime measurement (battery voltage, amount of flashlight output, etc.).

With the above in mind…

Using a boost-buck or a boost driver it is easy: slight increase in runtime. Switching drivers usually have well defined cell voltage windows and a boost-buck or boost driver would be able to run the emitter at the condition specified power/current from full battery until cut-off. With a buck driver, at some point battery voltage would get close enough to the emitter Vf as to force a reduction in driving current / emitter power. With a lower Vf emitter the regulated window is larger (coupled with a little bit higher efficiency), so runtime at selected current or emitter power is larger. However, high Vf emitters (slightly less efficiency) also cause the driver to stop switching operation and reduce current and power sooner, this means the runtime would be larger in this particular case for a high Vf emitter (if condition allowed); and thus, comparatively speaking the low Vf emitter would have less runtime (with these conditions) because of a higher runtime window at full power.

With linear drivers (regulation using MOSFETs as variable resistors) a low emitter Vf reduces runtime, this is because the window at which current remains constant (battery voltage > emitter Vf + other component voltage drops) enlarges (causing higher average battery drain), so the amount of regulated time is larger but total runtime gets reduced. Regulated time is a fraction of total runtime, by the way.

With unregulated MOSFET drivers the answer is @#$% easy: less runtime. This is because the larger the difference between battery voltage to emitter Vf, the more the driving current (and emitter power, lemons, etc.).

Note: had to edit this more than once. If you find something worth being corrected, say so. Thanks!

Tailcap amps?

~19.5A with a VTC5D almost fully charged

Yes something like that but with H,M,L no memory and no thermal regulation. Who wants thermal regulation anyway? That ain’t for serious modders :laughing:

Well, the CULPM1.TG perform worse than the CSLPM1.TG

CSLPM1.TG 6.3A - 1200 lumens at 30 sec

CULPM1.TG (from Convoy)

5.7A 1160 lumens-
7A 1135-
8A 1135-

same reading for both 7 & 8

It’s still barely an improvement

EDIT: Turns out I damaged the led at the beginning when I shorted a wire on the reflector turning purple.

New led at 7A gets 1300 lumens. Increasing to 8A only gets 13 lumen gain. I’ll be driving these with a 50E in Convoy’s ramping driver for 7A

what host and reflector size did you test this on ?

Convoy L21A

Turns out I damaged the led at the beginning when I shorted a wire on the reflector turning purple.

New led at 7A gets 1300 lumens. Increasing to 8A only gets 13 lumen gain. I’ll be driving these with a 50E in Convoy’s ramping driver for 7A

6A achieved just above 1200.

I just realized the CSLPM1.TG & CULPM1.TG are different in size, the led, not the surround part, not sure what that’s called?

The w2.1 is smaller or is it just my eyes fooling me?

Must be an optical illusion. The distance of the emitters to the camera lens in that photograph is also unequal, which also affects assessment.

Counted pixels there and both come out to 1.59mm wide(the vertical dimension in this pic) based on 3.00mm vs 4.00mm package size. Illusion indeed

Awesome, thank you for confirming. I can finally stop staring at them now :person_facepalming:

Can anyone confirm this is constant current? I want a driver with regulation for the W2.1

7A is the lumen limit for this led

The link in your post is broken, Funtastic, missing “l” at the end. I fixed it in my above quote of yours.

That driver features a sense resistor onboard, these are used for regulation. I'd expect it to be constant current.

Thank you

I want something better than Convoy’s drivers. What should I get that has decent regulation?

One other question, does that 8A buck driver from Convoy offer better regulation? I’m not familiar with buck drivers