Hi all I just recieved my Skyray King 4 x XM-L2 from Willbuying. I turned it on and was not impressed with output, so I decided to open it up and see if I could fix it up a bit. I have searched the threads and was unable to find anyone that has worked on the driver that mine is using. I am wanting to find out what is limiting the output and try to increase the current. Any information would be great and if there is a thread on this driver, please let me know.
I also know that the wire says 28 gauge and I have read that this can be a limiting issue. The wires are also quite long, but if there are other things I can do to this driver to boost output I would love to hear. Thanks for the help.
My first time posting an image, so hope it works: 
https://budgetlightforum.com/t/-/18688
https://budgetlightforum.com/t/-/19263
This thread might also be helpful:
I hadn’t found those. I will give them a read tonight.
Sean
I read through the threads listed above and they are in fact similar to the type of driver I have. Which is encouraging. Unfortunately they are different enough that I would be uncomfortable drawing my own conclusions as to what I should be adding to my driver to boost the current.
As mine is a 4x emitter it seems that there should be 4 sets of resistors to add to, but I am not sure which groups I should be looking at. Also, the resistor types on mine are different than the ones in the previous threads, so I am not sure what resistors I can add to them and exactly where. There do appear to be empty resistor spots on two sets of resistors at the bottom of photo and to the right of those.
I have a roll of the 30k 303 resistors that I read about on a previous skyray thread (hilarious how small they actually are), but don’t know if I can use these. I also placed an order last night for the 12r resistors mentioned in the above posts and am hoping that I can use them on this driver, once I have gotten some more education on the matter. As I have no experience working on the se lights, I am really limited to copying someone elses work or getting a detailed explanation as to what goes where.
I really any appreciate help and if more information is needed than what I have made available, please let me know and I can dig around somemore.
Thanks.
Sean
This one only uses two of the three 'channels' on the driver PCB, each channel running two LEDs in parallel. The third unused channel is at the top of the pic, where the empty spot for the FET is (the big black square thing with two leads).
So there are two channels in use, the middle and lower, there's a set of three resistors for each channel that set the output. The two in-use channels have a 4th resistor (installed upside down on yours, look on the other side and they'll be marked '000') stacked on top of one of the 3 main ones, these are very nearly but not quite zero ohm parts (note that the unused channel has the 3 main resistors, but not the 4th added '000' part). Adding more nearly-zero-ohm 'resistors' will raise the output... somewhat. In stock form with those 000s in place it's very nearly already direct drive and turning it up more won't net you very much. 4 cells direct drive into 4 LEDs, it's only going to do so much in that configuration, might as well think of it as four single-cell lights that share a common housing.
Thanks for the detailed explanation. I am not trying to absoluely max out the output of the light, just increase it some. It didn’t seem that much brighter than some of my other single emiter lights. It is brighter, just not on par with what I have seen in some of the other Skyray threads.
If the resistors are not really the limiting issue, do you think that I could get a significant boost by shortening the wires to the LEDs and swapping out the 28 gauge for 22.
I am trying to get this light ready for a Devils river trip that I am taking next month and am hoping to wow some of my non flashlight buddies. Again. Thank you for the help.
Sean
I think my question would be:
If this was your light and output felt a little low, what would you do to it? I generally defer to the advice of the experts on this site, so I might as well ask directly. Thanks
Sean
Replace the LED wiring with 22AWG (the switch wiring doesn't matter, leave it as-is, it only sends a temporary ground to signal the driver). Use short pieces of the original LED wiring to jumper across the resistor packs.
Your choice of cells will determine how much current it gives, there's just not much headroom left in the driver. The 3-LED Kings can be increased more, as there's 4 cells powering only 3 LEDs. 1 cell + 1 LED x 4 isn't going to go much farther than where it is now. And heat will be an issue, it shouldn't damage the light to get smokin' hot but it's kinda impractical to wear welding gloves all the time.
I think that your idea of shortening up the wires / swapping thicker gauge wires may net you a little gain. After that, your limiting factor may very well be your batteries, spring resistance, etc. XM-L2 lights without a boost circuit seem to be highly sensitive to cell type.
Before diving too deep it would be interesting to measure what kind of current you are seeing at the LEDs so that you can have a baseline to compare future modifications against.
+1 to heavier wires and to using a good 18650, like the Panasonic 10 amp. It really isn't going to get "noticeably brighter". If you think this output is "not that much more" than a single led, then really it's not worth messing with it. In order to know how much brighter it is, you would have to be able to read lumens output to know for sure. Definitely, it is brighter than a single led light, but the difference between 1000 lumens and 3000 lumens is not as much as one might think, especially when this is a floody light. When you have a floodlight, the light brightens up such a large area, (compared to a thrower style), that you think it's not all that bright. In actuality, it is brighter, but the area is so much larger that effectively, one small part of the bright area is not as bright as a thrower would be. Does that make sense?
Anyhow, these lights are for lighting up a large area close up. They are not much good for distances past 30-40 yards.
Once again. Thank you for the advice. I am going to swap wires and good batteries and see where things stand. The output as I said is brighter than my other lights, I think I just get expectations pushed sky high when I see some of the amazing things some of the members do here on this site. I will post back when I have the mods completed. Thank you.
Sean
Sean, like Old-Lumens pointed out, and you have certainly realized, our perception of brightness and lumens unfortunately is not a linear relationship. It seems to take about four times the lumens to appear twice as bright to our eyes (those are HIGHLY unscientific figures, meant to be used as an example only). Beam pattern and tint also play tricks on our perception. Our eyes (and mind) apply a lot of compensation to what we see. Think about how we perceive light on a cloudy (but bright) day vs. a clear and sunny day, moving from a dark to light environment, or a light to dark environment. I don’t know if you’ve ever used tinted goggles, but the mind even seems to compensate for tint after some time.
Flashlights are still a very fun (and addicting) hobby! 
This what i done with a 4x xml kung.
hate to thread jack…anyone know of a source and/or have a button for the switch for the SRK??
I can still turn it on, if I use a stick or pen……
My son some how lost it at the overnight scout campout…
Thanks
Tony
I think I got he same light. Upgrade Version! SKYRAY King Real 3000 Lumens 4x CREE XM-L2 T6 LED 3-Mode Flashlight(Special Offer)
With Sony laptop pulls I see 5 amps across the driver. All I can tell from my old 3-led (T6) is the temp seems warmer from memory. What’s the opinion on a driver swap or is it worth it?
Thanks