AKOray K-106 LED Upgrade

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brted
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AKOray K-106 LED Upgrade

Here is an upgrade I did on my nearly new AKOray K-106 3-mode programmable light. I liked pretty much everything about the light except that it wasn't as bright as it could be. So I bought a Cree XP-G R5 LED from KaiDomain and put that in there. The upgrade itself was pretty easy because the original LED and board were not even affixed to the pill. So I just had to unsolder the two wires to take out the old one. Once I had that out, I found a decent size hole, maybe 10mm across underneath. That seems kind of silly: here's a board that gets pretty hot and they put air underneath it? It would be better to fill it in, I guess, but I just wanted results. I put some STARS thermal compound that I got from DealExtreme and soldered the new LED in place. I didn't want to use an epoxy in case I didn't like the results and, I don't have the FUJIK thermal adhesive in yet from another order form DX. It was a little tricky getting the LED centered and I still don't have it quite right (I'll add some pictures tomorrow).

Here is the LED soldered into place (the little drips were there when I got it, the fried looking black lead is me getting sloppy with the soldering iron):

LED soldered in place

 

Here is a look in the reflector. The hole at the bottom of the reflector is made for a larger XR-E so there is space around it and the LED probably doesn't sit up quite as high in the reflector as it should. Notice it is also a little off-center. When I took it apart to take these pictures I was able to center it better. I also knocked down the overly large blob of solder on the red lead that you can see above (it was flattened by bearing against the bottom of the reflector).

LED and reflector

Results? The reflector is made for a Cree XR-E LED so the hole is bigger than it needs to be. There is a dark blotch on one side of the hotspot, maybe because the LED is still a little off-center (doesn't really show up in these pictures, but it is easy to see when the beam is moving). The increase in output doesn't seem that noticeable. Here are some side-by-side shots vs. a Fenix L1D (with a Cree XR-E Q5) before the upgrade and after:

On NiMH batteries. The first picture is the upgrade, the second is the original. At 1/25th second:

 

Same thing at 1/100th second:

 

Same thing at 1/1600th second. The hotspot is bigger with the upgrade, but loses some intensity. I think before the L1D was brighter and now they are closer to being equal. So a little bit of improvement, but it's not dramatic.

 

 

Now with a fresh lithium-ion battery in each at 1/25th second:

 

Li-ions at 1/100th second:

 

Li-ions at 1/1600th second. Same sort of results as before. Whereas before the K-106 lagged a little, now it is closer to an even match, with 106 having a bigger hotspot. In these pictures, the beam actually looks like it improved, losing the donut of darkness that is typical of the XR-E. I could try putting some shiny foil underneath the reflector to see if that helps the new beam.

 

 

Now for some test outdoors. These are 4-second exposures. The stick in the ground is 25 feet away and the beam is focused on the fence posts at the center of the picture which are 120 feet away.

Here is the L1D on a NiMH battery:

Fenix L1D NiMH outdoors

 

Here is the AKOray. It's a little blurry, but you can tell there is less throw because the fence posts are almost invisible. The L1D has a smooth reflector which really helps throw:

AKOray K-106 R5 outdoors

 

Now here is the AKOray with the original LED, taken a couple of months ago:

NiMH  High

 

Here is a zoomed in detail of the fence posts for the L1D, AKOray R5, and AKOray Q5 original:

Fence L1D NiMH AKOray K-106 R5 fence AKOray K-106 Q5 original fence

 

Now the L1D on a li-ion battery:

Fenix L1D Li-ion outdoors

 

And here is the AKOray on a li-ion:

AKOray K-106 R5 li-ion outdoors

 

And the AKOray with the original LED from a couple of months ago (kind of hard to compare since there were no leaves then):

Li-Ion  High

 

Now here is the detail of the fence posts for all 3: L1D, AKOray R5, and AKOray Q5 original:

L1D li-ion fence KOray K-106 R5 fence AKOray K-106 Q5 original li-ion fence

 

Battery Life

The battery life should be the same, I would think. The driver should be regulating how much voltage or current is going to the LED. But in my test it seems like the XP-G draws a higher current, but that doesn't shorten the battery life too much (I paused the test at 2 hours, 26 minutes to check the battery and it was below 1V, so I stopped testing and couldn't get a reading on the current). This may have more to do with the state of the battery, though both times I was using a 2000 mAh Eneloop.

 

Time (hr:min) Volts (XRE) 
Current (mA)Volts (XPG)Current(mA)
0:00 1.45 11901.3451220
0:15 1.31 9501.2811140
0:30 1.28 8801.2761130
0:45 1.26 8501.2701110
1:00 1.26 8401.2641080
1:15 1.25 7101.2551070
1:30 1.24 9301.2481050
1:45 1.23 7801.229990
2:00 1.21 7501.200930
2:15 1.18 7201.147770
2:30 1.11 5600.970 (2:26)n/a
2:45 0.92 n/a  

 

On a lithium-ion 14500, it looks similar. The current draw is higher and the battery life is shortened a little (maybe 5 minutes if I had stopped these at 3.60V):

Time Volts (XRE)
Current (mA)Volts (XPG)Curent (mA)
0:00  4.21  610 4.19 670
0:15  3.91  660 3.88 750
0:30  3.69

 720

 3.65 820
0:45  3.55

 770

3.52 860

 

Summary

This was a decent upgrade, but spending $10 to upgrade a $20 light and improving the output only a little bit probably doesn't make any sense. At the same current, the R5 is only 22% brighter than a Q5 (and I have not way of telling if this LED is really an R5 since R3 and R4 LED's don't look any different). It would be good if AKOray would upgrade the K-106 to a XP-G, drive it a little harder, and add a smooth reflector designed for this LED. Then they would really have something.

I have a couple of XP-G R4 neutral tint LED's on the way. If the tint turns out really good, I might put one of those in the K-106.

Edited by: sb56637 on 02/14/2012 - 08:18 Reason: sb56637 replaced budgetlightforum.cz.cc with budgetlightforum.com via Scanner Search and Replace module.
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Very cool modification here brted, thanks for sharing!  Can you notice any improvement in efficiency with the R5?  How's it perform on low mode?

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Don
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My guess would be that the battery life would be the same as the driver is almost certainly putting out the same current at any given setting. My guess is more light for the same amount of time. But I've been wrong before and doubtless will be again. What it should do is allow a lower setting for the same amount of light as long as you are quick enough when programming it.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

brted
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I haven't done a run test, but I am thinking it will be about the same, like Don said. The low seems to run about the same too, maybe it is a tiny amount brighter just due to the higher output of the LED, but the draw is the same. However, I was able to go from a 70mA draw to a 40mA draw by playing around with the low some more (on CPF some guy was asking how low people could set the light on a AA Eneloop). Some people like a moonlight mode, but 40 is really too low already, about like the iTP A3 EOS low which is 1.5 lumens. One person got theirs to 10mA at which point I think you could look at the LED (a fraction of a lumen).

brted
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Finished the runtime test. The current draw seems a little higher and battery life is a little shorter. Not a big difference though. I imagine the driver supplies a certain voltage to the LED and it may be that the Vf of the XR-E was a little lower than the XP-G and at the voltage supplied by the driver, the XP-G is drawing more current. Also I have been playing around with the mode levels on the light and maybe that is a little different, though I doubt it because High is the easiest level to set.

gcbryan
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Nice review. It looks like the camera settings with the slower shutter speed are more indicative of the usual characteristics of XP-G vs XR-E which would be a larger hotspot but slightly less bright with less bright spill. Is that more or less what you observed and commented upon?

I participated in one the Akoray low, low threads on CPF as well. I was sceptical of some of the low current draws initially since I had played around with my K-109 and couldn't get below .79 mA or something like that. After someone mentioned figures like .50 mA and then .20 mA I begain to play around with it while using a multi-meter and I eventaully got down to .24 mA as well.

I do like to get the low as low as possible on any light that can get real low. In a tent camping or hiking at night in an emergency it's amazing how much 1/2 lumen is and even the smallest battery will do at that level.

I've been wondering when Akoray would come out with a XP-G in one of these programmable lights. I'm not sure if I would upgrade since I already have a XP-G. It's kind of nice to have a small light like that that can throw a bit with a small reflector. I'm not sure that a XP-G and a small reflector are going to do much in that department.