L0D Q5 - Come on Fenix I want one.

[LA OZ]

All of its bigger brothers have the Q5. I believe Fenix should bring the Q5 version out asap. What do you guy think?

Here is the link of probably Korean origin http://o--o.yupoo.com/

 

[MikeSalt]

Actually, you do not want a Q5 in an L0D-CE. The Q5s typically have a higher forward voltage than the Q4s. With the voltage sag under load of AAA cells, even with the regulator doing the best it can, the Q5 will run for less time than the Q4. And then, you would get only a marginal, barely noticable increase in brightness.

 

[LA OZ]

Then there is L1D Q5 which uses 1.5V battery. How does it work? If what you said is true, Fenix has a challenge to make it possible. :naughty:

 

[Crenshaw]

Althogh i would like one too, the difference in output would be hardly worth the upgrade Im looking forward to R binned LODs, THAT would be interesting

Crenshaw

 

[Ryanrpm]

Does anyone know of a chart anywhere that lists all of the bins and emitters with their respective lumens per watt?

 

[orbital]

Does anyone know of a chart anywhere that lists all of the bins and emitters with their respective lumens per watt?

+

 

[Marduke]

The LOD already has the Q4, the Q5 really isn't that much better. You could NEVER visually see the difference.

 

[StarHalo]

Extrapolating from the chart, a L0D with a Q5 would be 80 lumens, a 5 lumen gain over the Q4 model. That's pretty much within the margin of error for a homemade lightbox, so not only would you not be able to see a difference visually, but even if you built your own scientific equipment, it would still appear the same.

Even if you went into the future and put in the R4 emitter, that'd still be only 98 lumens, a less than 25% gain.

 

[LA OZ]

hmm, the chart put things into perspective. Thanks, I will get the L0D Q4 ASAP :thumbsup:

 

[Illumination]

Then there is L1D Q5 which uses 1.5V battery. How does it work? If what you said is true, Fenix has a challenge to make it possible. :naughty:

My L1Dq5 choked on AAs. My P4 significantly outperformed it with alkalines that weren't brand new. In fact, it sometimes began to flicker, when the P4 performed perfectly.

On the other hand, my edgetac worked perfectly...not sure why...

 

[gadgetnerd]

You must have a dud Q5 Illumination, mine works just fine with 3.0V lithium, 1.7V lithium, fresh and old 1.5V alkaline, and 1.3V NiMH.

 

[Robocop]

This may be off topic however this is the first time I have actually seen the bin graph for the Cree parts.....with such a very small difference between the Q bins why even bother with different part numbers anyway? Based on what I have read it takes the a pretty good jump in performance to notice a difference anyway.

Based on that is it not safe to say the lowest value Q2 may look the same as even the highest Q5 to the eye....so why even bother with such small changes in the entire Q bin series? It looks as if with each step even up to the R bins that we have maybe a 7 lumen jump each time. Regardless of vf is it even really worth getting excited over such small increases?

It may be a weird question with an obvious answer but again I was shocked to actually see such small changes between each BIN.

 

[LA OZ]

In the current world we a living in, we have been brain wash to upgrade upgrade upgrade. If you are not careful you will end up .

 

[greg_in_canada]

They probably do it for non-flashlight lighting manufacturers. For example in a strip of LEDs you want pretty well matched colour and brightness or one or more will stand out.

Cree must have decided that it is a selling feature to have narrower bins than Luxeons do.

Greg

This may be off topic however this is the first time I have actually seen the bin graph for the Cree parts.....with such a very small difference between the Q bins why even bother with different part numbers anyway? Based on what I have read it takes the a pretty good jump in performance to notice a difference anyway.

It may be a weird question with an obvious answer but again I was shocked to actually see such small changes between each BIN.

 

[MikeSalt]

Then there is L1D Q5 which uses 1.5V battery. How does it work? If what you said is true, Fenix has a challenge to make it possible. :naughty:

I was referring to voltage sag under load. When a high current load is placed upon an AAA cell, its voltage will drop more than that for an AA cell.

For example, if I put 6xAA alkaline batteries (9 volt total) in my Roar of the Pelican flashlight, it would light only dimly. However if I put 6 NiMH AAs in there, at only 7.2 volts total, it will light up a whole field. Why? It is because the cells sag under load. The NiMHs will supply about 7.0 volts, whereas the alkalines will only provide about 0.5 volts per cell under load, which is only 3 volts.

This is a comparison of chemistries, but the cell size also exhibits voltage sag effects.

Hope that helps, Mike

 

[LEDninja]

Actually you would want the higher forward voltage of the Q5 if you want/may use 10440 with your L0D CE.

Actually, you do not want a Q5 in an L0D-CE. The Q5s typically have a higher forward voltage than the Q4s. The Q5s typically have a higher forward voltage than the Q4s. With the voltage sag under load of AAA cells, even with the regulator doing the best it can, the Q5 will run for less time than the Q4. And then, you would get only a marginal, barely noticable increase in brightness.

I have P3WC & P4WD L0D CEs and the brightness is only noticeable in direct A-B comparison. I can tell them apart more easily by the tint difference than by the brightness difference (71/65=1.09x).
A L0D Q4 would be 88/71=1.24x or 88/65=1.35x brighter.
A L0D R4 would be 115/71=1.62x or 115/65=1.77x brighter.
I think I will wait.

If you wanted the brightest AAA light now look at the Kai buckle light.
http://www.candlepowerforums.com/vb/showthread.php?t=187483

 

[Sir Lightalot]

My L1Dq5 choked on AAs. My P4 significantly outperformed it with alkalines that weren't brand new. In fact, it sometimes began to flicker, when the P4 performed perfectly.

If your particular Q5 has a high vf, then alkalines will struggle under the load and perform horribly. your P4 was brighter because they tend to have a lower vf and work better with alkaline. Nimh work best because they have a lower internal resistance, and like MikeSalt said, don't sag under load. i really think flashlight manufactures should tell consumers about this because i've seen a lot of people disappointed with the performance of their flashlights on alkaline.:shrug:

 

[JohnR66]

Isn't the LOD underdriving the LED? If so, would that make the difference between the two bins even less noticable?

 

[Illumination]

If your particular Q5 has a high vf, then alkalines will struggle under the load and perform horribly. your P4 was brighter because they tend to have a lower vf and work better with alkaline. Nimh work best because they have a lower internal resistance, and like MikeSalt said, don't sag under load. i really think flashlight manufactures should tell consumers about this because i've seen a lot of people disappointed with the performance of their flashlights on alkaline.:shrug:

Thanks; I think you are right. I'm sending it back in any case...I could live with the high Vf but the output is very ringy and discolored even on new cells.

 

[Luminescent]

Isn't the LOD underdriving the LED? If so, would that make the difference between the two bins even less noticable?

Yes this is correct, the difference would only average 7 lumens if you run the Q5 at 350ma, but at the lower drive used in the L0D it would be less (5 lumens or less), but the previous comment in another post about the Q5's having 'Higher VF' and being unsuitable for use in the L0D is total B.S.

This unfortunate piece of misinformation has come up OVER and OVER and OVER again, as folks quote others who heard it from others and pass it along, SO LETS STOP OK?

THERE IS NO REASON THAT THE CREE Q5 WOULDN'T BE WONDERFUL IN A L0D-Q5.

This 'Higher Vf' story seems to have originated with a TOTALLY LAME EXCUSE that was offered to explain the fact that a higher bin CREE part wasn't being used in the L0D some time back (by someone that should have known better).

When you are running a store and folks start to speculate about 'something better' coming along soon it tends to suppress sales (because everyone wants to wait for the new version). And, if you don't have that 'something better' to sell them, what do you do? Answer - try to con them into believing that the 'something better' isn't actually better at all.

If this B.S. 'higher Vf' story was actually true we would never have even got a Q4 in the L0D, because the original comment implied that ANY emitter higher than the P4 was just flat out a waste of time in the L0D (how convenient, since, at the time, the only emitter available in the L0D-CE was a basic CREE P4 bin version).

So let's put this silliness to rest once and for all . . .

Look at the binning chart posted above:

At 350 ma the Q5 will output 7% more lumens vs the Q4 right? (107 vs. 100)

Now look at the lumens-per-watt specs which is 94 lumens/watt for the Q5 vs. 88 lumens/watt for the Q4 (also about 7% right?)

It turns out that the Vf volts, Amps, and Watts are all interrelated such that, if the Q4 and Q5 have a 7% difference at 350ma and ALSO have a 7% difference in 'lumens-per-watt' at that same current level, THEN THE Vf IS STAYING EXACTALLY THE SAME.

If the Vf of the Q5 was really spec'ed Higher (as folks keep blathering), then the lumens-per-watt could NOT also increase by this 7% value, because a higher Vf would burn more watts and waste efficiency, reducing the lumens/watt (so the Q5 would miss it's 7% higher lumens/watt spec).

In fact, this is the whole point of spec'ing both the lumens@350ma. and the lumens/watt.

I know this is a little confusing, so let's look at some actual Vf numbers.

Suppose that you had a Q4 part that put out 100 lumens at 350ma with a Vf of 3.246 volts

350ma x 3.246 volts Vf = about 1.136 watts.

Now we take the Q4's 100 lumens divided by that 1.136 watts and get 88 lumens/watt (right on the Q4's spec)

100 lumens / 1.136 watts = 88 lumens/watt

Now let's do the same math for the Q5 using the SAME 350ma and the SAME 1.136 volt Vf number:

350ma x 3.246 volts Vf = about 1.136 watts (same watts as before).

Now we take that 1.136 watts, but this time divide by the 107 lumens that the Q5 is spec'd for, and we get about 94 lumens/watt (right on the Q5 spec)

107 lumens / 1.136 watts = 94.1 lumens/watt

We are working with whole numbers in the spec table, but within very close margins, everything lines up and the Q5 hits right on its lumens/watt spec.

With a higher Vf number, the lumens/watt of the Q5 wouldn't come out right.

For example, let's assume a TINY 10mv increase in Vf (3.256 volts instead of 3.246 volts):

3.256 volts Vf x 350 ma. = 1.1396 watts

With the same 350ma drive (because that's where lumens/watt is spec'ed), we now are drawing just a little more power (1.1396 watts vs. 1.136 watts) due to the higher Vf.

So let's see what that higher Vf and power would do to the lumens/watt:

107 lumens / 1.1396 watts = 93.9 lumens/watt (so the Q5 would not hit the minimum 94 lumens/watt spec)

Notice that even this tiny increase in Vf would cause the Q4 to fail its lumens/watt spec (so CREE would never ship such a part).


Conclusions:

1) The Vf isn't any higher on the damn Q5's than the Q4's (which everyone now knows work GREAT in the L0D) so let's stop repeating this silliness about the Q5's being 'no good for the L0D'.

2) Eventually we will probably see a higher bin part available in the L0D (Q5, R2 etc.).

3) One thing that IS true is that even if a higher bin part becomes available, the difference will not be all that noticeable at best (and could concievably be nonexistent, because the top of the Q4 bin is the SAME as the bottom of the Q5 bin). So, the L0D-Q4's available now are good enough to offer solid performance, and there is no need to beat your brains out worrying about it, if you don't want to wait for a Q5.