Is Q III overdriven with RCR123?

I read the review of the Q3 and it already has a boost circuit with a 3V 123 Lithium. Are we overdriven this light when putting a 3.6-4.2V ?
My single cell 3w clone flashlight uses RCR123 is direct drive and does not have a boost circult
.

Well, I know that if I run my Q3 with an R123, it gets much warmer than it does with a primary 123...

But it sure is bright!

i also run my Q3 with RC123s... voltage at 4.1vdc

Glad I saw this thread. I was wondering also about getting a small 1 or 2 CR123 cell led light for pocket carry and was also wondering is I could use rechargeable 123 in it.
How do you all think the rechargeable will function in a 1 watter? 3 watter?

I have a Q1 and a Q3 running on RCR123 and there seems to be little problem except the heat. Life of the lux 1 is expected to be severely shortened however.

The lux in the Q3 is a LUXIII and yes, the Q3 is severly overdriven with a RCR123 but the circuit is taking it fine. The life of the led won't last as long but then you can open it up and put in a TWOK or UX1K when these become cheaper in the future =P

Probably, it does get hot. But what is the real impact? I tend not to keep mine on for long periods at a time. Maybe the LED lasts 1/2 as long or 1/4 as long? How many hours is that? Isnt the normal life something like 10,000 hours? At $29 Im thinking wasnt there a Neil Young song about something like, the brightest lives burning out fast? It is really bright with an RCR123 in it.

Shortened Life is probably not linear, I'm afraid.. It might be shorted down to 100 hours.

But there are 3Volt batteries and charger also. Like this one.
Wouldn't these be safer? Or what's the difference?

Is it real? So far I havn't heard any REAL 3.0V rechargeables. Most are 3.6V even they claim is 3.0V

Take a look at this website. This shop has both 3.7 and 3.0 Volt charger and batteries.
There is a 3.0V batterie which uses an IC to reduce the 3.7V to 3.0V. It is recommanded for use with flashlights.
There is a link to this CPF thread.

I wonder if I should buy one...

I use a R123 in my QIII, as well as my Longbow Micra, and TW4 (E1e w/KL4) with no problems. A good rule of thumb is that if the light uses only a single 123 cell, no problem with the higher voltage. However, if the light uses 2 or more cells, it's a problem because the voltage difference in magnified two times or more. There may be exceptions to this rule, but I'm not aware of it.

goldserve wrote: "Q3 is severly overdriven with a RCR123 but the circuit is taking it fine."

With a RCR123 rated at 3.7V my Q3 draws 740mA
=2.74 watts

Please see:
Nuwai Q3 with RCR123 + Nano Charger

According to the specs - LumiLED Luxeon III pdf document page: 6 -
For 700mA Tj=25degC, Vf specs were: 3.03V min; 3.70v typical; 4.47V max.

Just as a reference on a regular 3.0V (non-rechargeable) CR123A the same Q3 draws 720mA.

I was told that if the battery voltage exceeds the Vf - the Q3's circuit stops working - ie: it is effectively by-passed - so the flashlight is in effect in direct-drive.

Please see Post #17 and #18 in this thread

As for a 1 watt Luxeon I - although I only tried the RCR123 with a sample of one - my S1801 1w Luxeon 1xCR123 drew 720mA = 2.66watts, and got very warm in a very short duration - I would not use a RCR123 with that flashlight..... please see the Nano charger thread above.

Please note I used the rated 3.7V for the RCR123 in my figures above - even though the RCR123 measured 4.07V freshly charged and 3.97V at the end of the tests - these were Open-Circuit measurements and voltage under load (as in use in a flashlight) is normally lower.

Im not an expert but from reading those threads I came away with the following conclusions:

1) running the RCR123s will possibly have no effect on the LED life

2) Running them may reduce the life of the LED by more than half, so that the brightness of the LED would only be at 70% of the original after 20,000 hours (down from 50,000)

3) At my normal usage, of say 2 hours a week (its probably less but it keeps the math easier) that would be 100 hours per year.

4) At 100 hours per year I would notice a drop to 70% brightness in the year 2205 or thereabouts. Or not.

5) If you used it much more, say about 2-3 hours per DAY, you would perhaps notice a drop in brightness in about 2025. We might even be around by then.

Yeah, not to get too into semantics, but from looking at the numbers, that as long as the circuit can take the voltage (which it seems it can) then with the rechargeable cell, the Lux III is driven near or just slightly over it's spec rather than significantly overdriven... Compared to the stock Q3 on the stock primary cell which significantly underdrives the Lux III.

Still, it comes down to this... If you have the ability to swap out the star, then the Q3 with a T bin star on the rechargeable cell is an impressively bright light for the cost and if you have to swap out the star after a couple hundred hours use then that still more than justifies the increased brightness and reduced cost of the rechargeables.

Plus, if you have a 2 stage tailcap, the amount of light that the low setting puts out is very, very usable...