I don’t have any 14500 batteries 
I did try a PowerGenix NiZn battery in it and got around 70 lumens at the start (call it 10% more than alkaline). The NiZn cells have a 1.65V starting voltage (also 10% more than alkaline).
I did try a lab supply set to 3.9V It drew 1.5A and put out 145 lumens. The alkaline cell drew 1.5A and the NiZn cell drew 1.1A
BTW, I got mine from TomTop
nice chart cainn [quote=texaspyro]
I don’t have any 14500 batteries I did try a PowerGenix NiZn battery in it and got around 70 lumens at the start (call it 10% more than alkaline). The NiZn cells have a 1.65V starting voltage (also 10% more than alkaline). I did try a lab supply set to 3.9V It drew 1.5A and put out 145 lumens. The alkaline cell drew 1.5A and the NiZn cell drew 1.1A BTW, I got mine from TomTop
[/quote]
Me too! 
Visually do you notice as much a variation in performance/brightness as the readings suggest there might be?
The OP’s deal is now “currently unavailable”.
Yeah I was thinking about this too….Does the higher numbers translate in brighter flashlights?
How do I measure those amps? Any apparatus needed and how to connect it?
Good question. The short answer is, yes and no, and not always as you'd expect based on the tail cap readings. The long answer is in the table below. I did some ceiling bounce lux readings at 2m with beeCam light meter on my phone:
| Current Draw | Lux (flood/throw) | |||
| NiMH | Li-Ion | NiMH | Li-Ion | |
| Sipik SK68 (Silver, from DD): | 2.15 | 1.16 | 16 / 11 | 31 / 22 |
| Sipik SK68 (Black, from eBay): | 1.10 | 1.46 | 22 / 16 | 51 / 35 |
| Unbranded (Silver, from TomTop): | 1.47 | 1.66 | 26 / 18 | 60 / 41 |
| UltraOK ZS-2 (Black, from eBay): | 0.61 | 0.76 | 12 / 9 | 32 / 21 |
| UltraOK ZS-2 (Silver, from eBay): | 1.12 | 0.95 | 23 / 16 | 41 / 28 |
| Ultrashine 3-mode (Black, from eBay) (HI) | 1.67 | 1.23 | 16 / 12 | 36 / 26 |
The results didn't always make a lot of sense to me, so I went back and did some tail cap readings again afterwards, but it turns out I got them right the first 2 times, so now I'm just left scratching my head as I look over some of the anomalies.
Of course one has to ask how much one can trust ceiling bounce lux readings done with a mobile phone. The answer is, probably not very much, and possibly doubly so given the particular conditions. All this has inspired me to get a proper lux meter.
Having said all that though, the silver TomTop clone is indeed the brightest of the bunch visually. I have no idea whatsoever what is going on with the DD SK68 on NiMH though. Just strange. The numbers change around a bit if you start swapping around tail switches, but not by much. Even when bypassing the tail switch on the DD SK68 completely the lux readings are pretty much the same (way lower than current draw would suggest).
Anyway, as potentially flawed as this comparison may be, it's been fun (I got to use tables!). Might as well add some beam shots too:
Left to right, top to bottom: UltraShine 3-mode, TomTop clone, SK68 (black), ZS-2 (black), ZS-2 (silver), DD SK68 (silver)
Note: No one out there should run off and buy a TomTop clone just because my results suggest that it's the brightest. Similarly, no-one should avoid a black UltraOK clone, or a Silver SK68 from DD, just because they fared poorly. There's so much variance between clones even of the same name, even from the same seller, that it's more about luck of the draw than anything else. You'd need to look at a sample size orders of magnitude bigger than mine for it to be valuable, but even then...
Thanks for taking the time to do this. Appreciated.
BTW - what emitter do these SK68’s use? XP-E or XR-E, they both have 3 stripes don’t they?
They’re almost always XR-Es. Q3 or Q5 bin mostly, although there are some Q4’s around too (manafont for example). But I don’t think I really even trust the advertised bin to be the actual bin anyway.
Heard from someone here (don’t remember who) that occasionally you might find one with an XP-E in it. Any yeah, 3 strips in the middle. See: Cree - Flashlight Wiki
Interestingly, none of those shown above were 7 watts as they are commonly listed for sale. From the huge sample of 1 light from BBQ SK68 clone lights bought off Amazon it did just hit 7 watts with 14500.
I noticed the quality has gone down a little on my last batch I ordered from TomTop (black ones). Ordered late September @ CAD5.35 each.
I haven't done any tail cap measurements but here are some differences I noticed:
I suspect this batch is either from a different manufaturer; cheaper parts used; or changed parts design so it's not easily repairable.
My TomTop clone breaks 7 watts (when measured at the tail, anyway) when using a Li-Ion hot off the charger (at 4.10+ volts). Measures around 1.85A. But you don’t get that for very long.
Great collection of info — deserves to be promoted/made permanent somehow.
Link to the tomtop 3mode?
> Link to
Problem is, there’s no way to link to what you’re describing — they don’t send the same thing each time, from anywhere.
You’ll double the output by setting them to wide beam - the zoom feature pays a very high price. I’ve verified this on basically every zoomie that has been through my hands.
overrated. I’m leaning these days to adjusting the zoomed beam to just above the castle-tower effect and living with a fairly decent semi-circle hot-spot at the expense of extra throw.
I tested the output at both wide and narrow beam. I slapped that table of results together pretty quickly without too much thought, so maybe it’s not obvious. There’s 2 values. First one is wide beam / second one is narrow.
What quality can be expected from this sk68: http://www.ebay.com/itm/300-Lumens-WC-CREE-Q5-LED-Zoomable-Adjustable-Focus-Flashlight-Torch-Lamp-3-Mode-/150816970535?pt=US_Flashlights&hash=item231d645727 ?
351 neg feed back for last month? I would stay away.
But for the question, of quality: YOU CAN NOT EXPECT QUALITY FROM ANY SELLER SINCE YOU ARE NOT LIKELY TO GET EVEN THE SAME LIGHT FROM SAME SELLER.!!