Does anyone know what the runtime of this flashlight is when set on LOW power?
Hi -- welcome to BLF!! I see this is your first post. Would help us if you provided an exact link, or tell us where and which exact model you got. Of course runtimes will depend on the batteries - what the mAh ratings are, how many, etc., so it would help to know what batteries you are using. Most multi-emitter lights use more than one cell, and on low will have 2-5 hours roughly, but if it's running on one 18650, then it's much shorter.
You can do some guesstimating, for example a 2000 mAh (milli amp hour) cell will run 2 hours on a 1 amp draw, but there's lots of other factors but some of them cancel out.
Thanks for the reply Tom.
This is the flashlight I’m getting . . .
With these batteries . . .
I doubt that you can run 7 x XML emitters with just one 18650 battery, you need at least 3 batteries… may work with 2 but very very short time.
Ohh, ok - I see now. Those batteries are very highly NOT recommended here, though they are extremely cheap which makes me even more suspicious. Problem is you don't know what you got when buying those cells - could be just "ok", could be total fake useless garbage -- no telling. The "low" mode on these type of lights is still pretty bright typically. On 4 quality cells, you should get 3-5 hours, depending, but on those cells, lucky if you get 2-4 hours I'm thinking.
It really would be best to charge them up and do a runtime test yourself. That is certainly not a common light here on the forum, so not sure what the draw would be to get any more specific. Maybe someone else can chime in and can be more specific -- sorry...
You have same battery warping 
Ultrafire 18650 3000mA exploded | Candle Power Flashlight Forum
Since the Amazon listing refers to TangsFire, thinking they are from TMART here: http://www.tmart.com/4.2V-600mAh-Charger-with-UItraFire-18650-3000mAh-3.7V-Rechargeable-Battery_p151658.html, though this is 2 cells, not 4, but priced accordingly. Yes, we generally stay away from these cells but you could get lucky with them. I would suspect they don't work too well in this type of light because the cells are in parallel, not series configuration, so the high internal resistance will be a factor. Of course on a low level draw, maybe not so bad...
Looks like XML2’s in the listing to me. That may or may not have been what they sent.
Those batteries are the big issue here. There’s so many variables to consider with __fire batteries that there’s no telling what they sent you. I wouldn’t expect them to charge, nor would I even try to charge them. The dangers of using low quality Liion batteries far outweighs the $10 life lesson.
I would get a Nitecore i4 charger, and 4 Panasonic NCR18650B 3400mAh protected batteries. This will be quite an expenditure at ~$60, but you get quality, safety, long run times, and incredible performance.
If you want to save some money, but still get good quality, I would go with Sanyo UR18650FM 2600mAh protected batteries. That should drop the total to ~$45.
Welcome to BLF 
Agreed on the batteries, when first time I joined this forum I was looking for the cheapest batteries around with the higher rating, turn out those are ratings are useless, same goes with the number of the lumens on the cheap flashlight
if you want one that gives out “big bang” out of your money instead getting that 7 LEDs “soda can” light
try this Supfire M6 instead and couple them with these batteries Panasonic PF from bang good and with coupon BLF it should lower it little bit.
even though the Supfire M6 only have 3 LEDs on it but it will put out more lumens than that 7 LEDs light
it might come up a little bit more than what you want to pay but you’ll get top notch light that will pretty much “WOW” everyone around you whose not flasholic
don’t be fool by the amount of LEDs inside the light, I used to think the more LEDs inside the light the brighter it will be but it’s not always the case.
I have the same light albeit it came with 6 XM-L2 LEDs from fasttech for less than $45 and I thought it would be a bargain, unfortunately the output was so-so and nowhere close to Supfire M6.
or if you want something bright but don’t care about the size… try TR-J18, these day you can buy one for about $45 and it will be brighter than both of them and you don’t have to worry about the heat from holding the flashlight
those soda can lights will get very, very hot in few minutes, it will be uncomfortable to hold it after 15 mins on HIGH mode
or if you want to save money for the future and be happy with 1 light ( btw there’s no such thing as happy with 1 light in this forum 
)
and if I knew then what I know now, I’ll buy Fenix TK75 and save me a lot of money as I’ll be happy with 1 light as it will give the best combination of both flood and throw, or maybe the cheaper BTU ( not really my favorite as it weight more than a brick )
other than that stick around BLF and lurk for more bargain( which there’s always one ) and ask more question before spending you hard earned money 
PS: don’t believe in those advertised “Chinese” lumens shown on the body of the light
Thanks for all the helpful replies from everyone. The exploding batteries thread scared the crap out of me. Is is a lot safer to just stick with flashlights with only one cell?
I think that’s sort of a loaded question.
If you have that flashlight with 4 nice, high-quality protected batteries (for example), that’s probably safer than say, a 1-battery flashlight with a knockoff UltraFire in it.
Storing energy in a sealed container is inherently risky. But so is moving down a highway at 70 MPH in a metal box that weighs more than a ton carrying gallons of flammable liquid. If you have quality protected cells and a good charger, then your risks are being mitigated.
The main risk with a multicell light is that if one cell runs down faster than the others, it can get reverse charged by the other cell(s) and then explode.
Reverse charging like this shouldn’t be possible in a single-cell light. I’m sure single-cell li-ion lights can explode, but it seems much more common in multi-cell light.
Suggestions:
- Don’t skimp on li-ion batteries. Invest in high-quality name-brand cells. In general if the brand name of your batteries has “fire” in it, avoid at all costs (except for Surefire). Good brands include AW, Panasonic, Sanyo, Efest, etc.
2. Never let your li-ion batteries fully deplete.
3. If you notice any abnormal behavior in your li-ion batteries, stop using them immediately and consider discarding them. This includes a cell that suddenly seems to have much reduced capacity, or one where you notice any abnormalities in the packaging (bulges, burn marks, etc.).
4. When using li-co chemistry always use “protected” cells. They have a circuit in the top that’s supposed to stop the battery from functioning in certain conditions conditions.
5. Also consider purchasing a flashlight with built in low-voltage cutoff. Many high quality flashlights, like Zebralight, have this. Most budget lights won’t, unless they’ve been modded to use a custom driver.
6. Invest in a quality charger that won’t overcharge your cells. And occasionally test the voltage on your cells to insure they are within parameters.
Thanks Firelight2. Good tips. So I’ve got some good suggestions for a flashlight and batteries. Does anyone have suggestions for a decent budget charger?
You mention testing the voltage in your cells. How would I go about doing this?
Welcome to the forum DaPhotoGuy !
Can you please post a macro picture with the reflector/emitters ? I am interested to see if you received XML or XML2 emitters.
Thanks.
Sorry. Haven’t gotten the light yet. What’s the diff between XML and XML2. To me XML stands for “Extensible Markup Language” B^)
Oh, ok.
XM-L is the emitter model. They are made by CREE.
XM-L2 is the new generation and is ~20% more efficient.
Didn’t see this suggestion for a charger “Nitecore i4 charger”. Well respected on the forum??
The i4 is a good entry-level charger. But they sometimes get warmer than they should and often only charge cells to 4.15v, but they’re reliable and safe.
The external difference between the XM-L and XM-L2 is that the former has a green substrate (the chip on which the emitter is printed) and the latter has a white substrate.
If you are still looking at this light, then the other Skyray Kings (3, 4 & 5 emitter variants) all suffer very bad PWM on low mode. Suspect this 7 emitter version will be the same.
I love my SRK, but I pretty much only ever use it on high. If you want less light, just use something smaller to begin with.
Hello.
I know I am digging up an old thread, however I just recently got the same light and I’d like to clarify one thing: While it is indeed 4 cell light, the cells are in parallel, so there is no danger of polarity reversal, even with different cells.
No low voltage protection though…