Review: KD 2 x Cree XML-U2 4+10-Mode 2200 Lumens Bicycle Light (picture heavy)

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ledoman
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Review: KD 2 x Cree XML-U2 4+10-Mode 2200 Lumens Bicycle Light (picture heavy)

I've got opurtunity to inspect very promising dual led bicycle light from Kaidomain.com.

http://www.kaidomain.com/product/Details.S023788

From the outer look it is the one of few latest clones of Yinding (Gemini Duo clone), so it is essentionaly clone of the clone. Wink

Here are the pictures:


Taking it apart was quite easy

The driver:


Internals - PCB:

Lenses:

Lenses can be simply replaced:


Opearating:

The light has three modes chosen from 10 brightness levels. It can be any combination you want. You can make it Low, Mid , Hi or Hi, Mid , Low or Low, Hi, Mid if you want. For this test I've choosen levels 1, 4 and 10. Strobe is hidden and can be reached with long press from off mode.Light is turned off by long press in any mode.

The light is powered by tipical 2S2P 8.4V battery pack.

Power usage

Connected to the battery pack:

Level1:

Level4:

Level10:

 

Beam on high:

Beam of 2nd generation Yinding to compare to:


Final verdict

Pro:

  • best user interface you can find in the budget bicycle lights
  • 10 levels of brigtnes to choose from
  • small and very light
  • nice evenly spreaded beam
  • overheating protection
  • XM-L2 U2 leds (despite title says it's XM-L)
  • 14.5W (2200mAh) to the leds
  • possibilities to exchange TIR lenses for wider angle

Con:

  • not the best heat transfer to the housing (Yinding has it much better)
  • no thermal paste (as usuall, but can be easily added)
  • can overheat at higher levels but it's ok when moving fast
  • cool white leds (neutral white would be much better)
  • not waterproof but can probably stand light rain


Overall very nice bicycle light for helmet use, specialy for MTB purposes. There are quite some improvement I would like to see, though.

Edited by: sb56637 on 09/02/2017 - 12:28
M4D M4X
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thanks for your review!

 

already member of M4DM4X.com ?

the best deals are waiting for YOU!

 

before you buy elsewhere mail me: MARTIN@M4DM4X.COM - i will try to save you money!

ledoman
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You are welcome. Feel free to comment anything. Shurely I have to correct/add something. This was more quicky one Wink

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Got any pictures of the battery pack?

ledoman
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There is no battery pack with this light. You have to use your own.

WarHawk-AVG
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Is there no thermal path between the star and the housing? I see two screws to the large oval shaped star…how does the heat get from that to the body?

Nice…pushing over 13 watts to the emitters…if it had better thermal management might even be able to push more

Possibly make a stinkpad with that large oval star (drill out the thermal path thru the dielectric, then press in some copper slugs for better thermal path from the emitters)

Still and interesting little light…

ledoman
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WarHawk-AVG wrote:
Is there no thermal path between the star and the housing? I see two screws to the large oval shaped star...how does the heat get from that to the body?

There is some thermal path over thin copper layer on the PCB you can see on the picture. Those small triangles then lay on the housing. I should make a picture.  Take a look to the pictures made by Garry on very same constructed light, just different driver. There is also some thermal transfer via two screws. PCB is 2mm thick, a little bit more than tipical ones.

The power used is just enough for that small light. Better heat transfer would help of course. As far as is being used as helmet light, there is just enough light if you are using some more powerfull on the bars.

WarHawk-AVG
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How much space is between the star and the driver, could say 1/8-1/4” of potting be applied behind the star and let harden before putting the driver in, not only adding more thermal mass but then a better thicker path for heat to flow to the body?

ledoman
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There is not much space left. Coil is almost touching the PCB. Then there are the wires, too. There is only some small space left on the both sides. PCB could be cut away on sides since on the other side there are TIR lenses leaving some space. Using artic alumina bond it is possible to stick there some small chunk of copper. I might just do something in this direction in the future.

ledoman
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Low voltage divider and thermal protection part of driver circuit. Don't know if it's very exact, but it's at least similar to what I've seen in HD-016 and another 10step driver at DX.

siata94
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Thanks ledoman. I keep thinking that eventually I will need to try one of these lights,
only if there’s a 2-cell case.

ledoman
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You may find 2 cell battery pack at some US seller. Alternatively there is reputable store at eBay->here.

ledoman
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I've measured when driver turns on yellow and red status leds indicating power exhausting stages. I've measured figures at battery side. There is some voltage drop involved at higher currents. The lowest current at level 1 is probably the nearest to the voltages at the driver terminals. At level 10 there is significant difference due to voltage drop in wires and connector.

Level 1 and level 10 voltages

  • Yellow turns on at 6.15V and 6.7V respectively
  • Red  turns  on  at  5.9V and 6.3V respectively
  • Red  blinking  at  5.7V and 5.8V respectively

Difference is not linear as the light starts dimming due to voltage drop below of the leds Vf.

At red blinking stage light tuns to level 2 or 3 and doesn't come up regardless if you raise the voltage. You would need to disconect the light from the power to get green status again. This is good if you're almost out of the power, but you'll still get low light for quite some time for safe return. Of course you can select lower levels by hand immediately when red status light turns on.

garrybunk
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Thanks ledoman for your review.  As I said over at MTBR, I may ditch my exact looking model from KD (though 4.2v with different driver) and get this one instead.  I think I will practice the potting method on my old one though.  My unit (without coil) has 6.3mm of empty space between the driver and PCB for potting. The thread on modding my light's driver (with pics of light) is here

siata94, I have this headlamp at FastTech on my wishlist for its 2 cell battery case (buy a battery case and get a free headlamp! Smile ). 

-Garry

My Bike Lights Thread, Optics (TIR) Comparison Beamshots, Diffusion Techniques


NOTE: Moving my photos from PhotoBucket to Flickr. PM me or post in the thread if you can’t see my images and need me to fix or send a gallery link. PhotoBucket images should remain visible until November 2018.
ledoman
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Thanks Garry. Would love to see how your modding turns out also all about potting stuff.

Battery case from Fasttech you pointed out is 2P1S (4.2V) while with this "KD2" you would need 2S1P ie. 8.4V, so no go. But it could be good for your KD version.

garrybunk
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ledoman wrote:
Battery case from Fasttech you pointed out is 2P1S (4.2V) while with this "KD2" you would need 2S1P ie. 8.4V, so no go. But it could be good for your KD version.

Sorry, forgot to point that out.  It's likely moddable though to 1P2S. 

-Garry

My Bike Lights Thread, Optics (TIR) Comparison Beamshots, Diffusion Techniques


NOTE: Moving my photos from PhotoBucket to Flickr. PM me or post in the thread if you can’t see my images and need me to fix or send a gallery link. PhotoBucket images should remain visible until November 2018.
Essexman
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Nice review, thanks for taking the time.

Re heat sinking – it needs more. Most of these lights need more heat sinking.

garrybunk
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I contacted KD about buying this lights driver (this "10-step user programmable" one).  They will sell the driver for $8. They also reminded me that for my 4.2v version light the LEDs would need rewired to series (I appreciated hearing this from them as it showed me they had some knowledge on what they were telling me about driver replacement). If interested, you would just have to contact them and say you wish to purchase the driver used in bike light sku#S023788.

-Garry

My Bike Lights Thread, Optics (TIR) Comparison Beamshots, Diffusion Techniques


NOTE: Moving my photos from PhotoBucket to Flickr. PM me or post in the thread if you can’t see my images and need me to fix or send a gallery link. PhotoBucket images should remain visible until November 2018.
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This "10-step programmable driver is now available for purchase here: http://www.kaidomain.com/product/details.S023801 .

-Garry

My Bike Lights Thread, Optics (TIR) Comparison Beamshots, Diffusion Techniques


NOTE: Moving my photos from PhotoBucket to Flickr. PM me or post in the thread if you can’t see my images and need me to fix or send a gallery link. PhotoBucket images should remain visible until November 2018.
ImA4Wheelr
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^ Thanks garrybunk for getting that driver available.    I just bought one.

ledoman,

Thank for this very informative review.  Nice work.  Although the thermal path to the housing appears limited, it might do the job fine at moderate currents.  Depends on if that copper trace covers the whole MCPCB and how thick it is.  Also, there appears to be some room for upgrading behind the MCPCB.

EDIT: Guess I didn't look at the pictures close enough.  I just noticed this post by ledoman:

There is not much space left. Coil is almost touching the PCB. Then there are the wires, too. There is only some small space left on the both sides. PCB could be cut away on sides since on the other side there are TIR lenses leaving some space. Using artic alumina bond it is possible to stick there some small chunk of copper. I might just do something in this direction in the future.

hank
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I recall reading elsewhere that the original Gemini Duo and the earliest clones under the Yinding name had a solid aluminum wall across the middle of the housing as a thermal path, ‘til early in 2014 somewhere — but those have disappeared, because people copied the outside appearance while cutting material and build time, gutting the insides. Somewhere I saw someone had just weighed the good ones vs. the recent ones — lots of material gone away.

Has anyone tracked down the early design anywhere?

This is like the ‘solid pill, hollow pill’ thing, I guess.

garrybunk
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It's the same as the SolarStorm X2's; all the good ones appear to be gone. 

-Garry

My Bike Lights Thread, Optics (TIR) Comparison Beamshots, Diffusion Techniques


NOTE: Moving my photos from PhotoBucket to Flickr. PM me or post in the thread if you can’t see my images and need me to fix or send a gallery link. PhotoBucket images should remain visible until November 2018.
ledoman
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hank wrote:
I recall reading elsewhere that the original Gemini Duo and the earliest clones under the Yinding name had a solid aluminum wall across the middle of the housing as a thermal path, 'til early in 2014 somewhere -- but those have disappeared, because people copied the outside appearance while cutting material and build time, gutting the insides. Somewhere I saw someone had just weighed the good ones vs. the recent ones -- lots of material gone away. Has anyone tracked down the early design anywhere? This is like the 'solid pill, hollow pill' thing, I guess.

Hopefuly this Yinding is a good http://www.gearbest.com/led-flashlights/pp_124468.html.

I was talking to them to get one to test. Will see in a few days if I'm going to get one. Also I think we can get some coupon afterwards. It is just light head no other shitty accessories. If it's really good one price is not so high. Combining with this battery case can make really good light setup for helmet use.

hank
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>> all the good ones appear to be gone….

> Hopefuly this Yinding is a good

Did you decide to get that one? Any idea if it’s got heatsinking?

and

has this one come to anyone’s attention?
http://www.gearbest.com/led-flashlights/pp_71062.html
UltraFire HD-16 Cree XM-L L2 2400lm LED White Bicycle Headlight Flashlight 4 × 18650 with Head Strap Battery Charger

“Uniquefire” in the pictures

ledoman
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Yes I've decided to get Yinding. I'm just waiting to be sent out. It should have good heatsinking and XM-L2 U2 1A leds.

If you want to buy it including battery pack then use coupon "Yinding" for $38.04 shipped. It is currently the most wanted light there over at MTBR.

hank
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> Yinding
OK, we need something, I’ll go with that one.
I don’t see anything specific about the included battery pack — I know those are iffy — any idea how good that part of the deal is?
Well, I’ll know in a while.

ledoman
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Unfortunately I don't know the battery. We think we have found original manufacturer of Yindings and the first batches, before clones came out, and even my 2nd gen. have had quite good batteries. Not the best, but reasonably good. At least I can speak for mine sample. I can ask over at MTBR if the manufacturer can give some figures about real capacity.

hank
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Thanks, I figure on supplying my own good batteries, but I’m wondering about the battery box — does it have a protection circuit built in, so I can use unprotected cells?
And of course is the included charger a threat to life, or acceptable, since so many cheap chargers fail HKJ’s tests I don’t trust them much.
I’ll comment when mine gets here, but it’ll be next year sometime.

ledoman
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About battery box you should read this thread and yes it has protection built in. It is safe to use unprotected but brand cells. Can't tell anything about charger. I've found reasonable good ones at ebay. Search for "8.4V charger P7". Still would test each if it is CC/CV.

hank
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> Battery box
Thank you! that’s a good one. I’ll have two, because I’d ordered one of those weeks ago that’s en route.
Oh well, never hurts to have a spare.

> test if it is CC/CV
If you have a pointer to how to test that, I’d like to know. I’ve never known how to test chargers

garrybunk
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hank wrote:
ledoman wrote:
test if it is CC/CV
If you have a pointer to how to test that, I'd like to know. I've never known how to test chargers

See post #12 in this thread.  Perfect cheap solution.  (They are cheaper from China, but I linked a good fast US Seller.)  To look for CC/CV just watch that the current is constant during the beginning up to somewhere around 8.0v (I'm totally guessing on the 8.0v part) and then see that it switches to maintaining constant voltage with current slowly dropping down from where it was.  You may not see the constant voltage on the display (because I'm guessing you'll be seeing the battery voltage rising), but you will see the current dropping.  The only two chargers I've tested this way just maintained CC right up to full charge / termination voltage.

Ledoman (or others), please correct me if I'm wrong.

-Garry

 

 

My Bike Lights Thread, Optics (TIR) Comparison Beamshots, Diffusion Techniques


NOTE: Moving my photos from PhotoBucket to Flickr. PM me or post in the thread if you can’t see my images and need me to fix or send a gallery link. PhotoBucket images should remain visible until November 2018.

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