Review - Bike Light/Headlamp with 2 XM-L T6 from EachBuyer

LED Flashlights – General Info 18650 Flashlights
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thx! love all the useful info to be found on this forum.

the Yinding sold here there and everywhere but I have not found it without batteries would like to use it with the Pannova holder and some “real” batteries

http://www.fasttech.com/product/1443727-yinding-2-cree-xm-l-u2-4-mode-1800-lumen-white

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He's talking about this one also sold by Simon on Ali, though he doesn't appear to have the NW version anymore. As with the X2, MTBR peeps are finding these Gemini Duo clones to be of varying quality. Here's a link to the original Gemini light. Also of interest is this one at Lightmalls, head only, with the programmable 10 step driver (driver reviewed by Cat-man-do on MTBR in his KD Tri-clone review). I've wondered about picking up this one myself as I'm afraid my X3 will suck the battery down pretty quick.

Edit - he beat me to it.

-Garry

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and as a roadie what I would really like to see is a light with more of a 16:9 format beamshot ie not circular as a flashlight

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Nisse, you see the link to the "head only" Duo clone from Lightmalls I linked in my post above? (I edited my post and added it).

-Garry

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I'm totally with you nisse on the wide beam since we see a wider horizontal field than a vertical field.

Not sure it this is as wide as you would like, but here are a couple beam shots from Garry's X3 pictured above (am I right about that Garry?). Stock and Modified (Mouseover):

Distance to the tree is approx. 185 feet. Approx. 275 feet to the house off to the left of the tree.

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Yes, correct. The X3 was recommended to me by a user over at MTBR when I asked about a floody light. In those pics only the tint was changed (simple emitter swap). I didn't get the photos from the same exact setup (I tried my best to recreate the setup), but you can see the beam pattern is the same..

For comparison, here is a photo (from same setup as "prior to mod") of a standard MagicShine MJ-808E clone on high with mouseover to the X3 prior to mod:

There you can see the difference from the larger lens light (39mm) to the smaller triple.

-Garry

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wide and low is the way to go on road like this http://www.peterwhitecycles.com/schmidt-headlights.asp

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Hey Garry,

You have any images of your X3 driver?

I Googled a bit, but I can't seem to find any in the cloudiness.

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Yes, my photobucket album of the teardown of it is here. Here are a few pics:

and

Over at MTBR they always said the SSX2 drivers which had the terroids were the good ones. In fact there is a post somewhere where a seller had posted comparison driver pics with notes about component differences. (Sorry, it's a huge thread to wade through - blame lefteye!)

-Garry

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What is a reasonable guess as to driver efficiency in these lights? If I have 4.96A coming in (my 2.48@8.2v x 2), how much should I expect is going to the LEDs?

-Garry

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Thank you Garry. Not enough of the driver exposed for me to see what I was hoping to see. No biggie though. I take it the LED's are wired in parallel and you battery pack is 2S (8.4 volts charged)?

I was studying my driver and it looks like can probably handle 3S maybe 4S cells since most of circuit's voltage is regulated by the QX9920 buck converter. I will try it out atleast.

I will be trying to swap out the MCU for an Attiny13A (loaded with JonnyC's STAR momentary FW) so that I can have all the modes I want and a different UI. Might even increase the max current more as it will have a timed turbo. The High Mode (pre-turbo) level will still be too high for stationary use, but I want it for riding. The Turbo mode will be for when I really want to blast out some light.

That X3 of yours appears to be much more substantial than my X2. The "pills" and the casing walls look thicker. Although similar, it looks like a different class of light. I will be on the look out for a good deal on one of those.

32

Yes, my emitters are in parallel with a 2S2P battery pack (I only run 2S in my Pannova for testing).

-Garry

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I don't know your driver's efficiency, but it would be real easy to measure. Just do the following:

  • Disconnect power to your light.
  • Cut and strip the ends of 2 wires. Say 6 inches long each.
  • Use a couple of wooden cooking skewers to wedge them into your DMM ports for 10A and for Common.
  • Remove the screws that hold your driver and pull back enough to have room to unsolder one of the sets of leads going to your LED's (Can be either the positive or the negative).
  • Solder one of the wires coming from your DMM to the LED lead and the other to the pad on the driver.
  • Reconnect power to your light and turn on your DMM to the Current setting.
  • Go through the modes and record the current measurements.

Here is an example of what I mean by cooking skewers. One of those wires is going to the LED Negative and the other to the driver's Negative LED pad.

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If you remember, back in this post I had measured 1.88A at one of the emitters (original emitters prior to swap and after scratching away new solder point). That was with different batteries, but results should have been similar. 1.88A per emitter doesn't make sense with 4.96A coming in from the battery. 4.96A / 3 = 1.65A (that's 100% efficiency I guess).

-Garry

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Sorry Garry. I forgot about that. I should have also realized that you know how to properly measure emitter current.

I'm not good at estimating Vf of emitters or voltage sag. I calculate 47% (18.3 emitter watts / 38.7 watts cell output) efficiency. That sounds too low (See EDIT2 below), but I actually think my calculation has assumptions that result in overstated efficiency for the following reasons:

  • The Vf in the below calculation is too high because I used Match's Vf of the XM-L2 on copper. You stock emitters were XM-L's on aluminum (right?). If so, you Vf would be higher.
    • 3.25Vf * 1.88 amps * 3 emitters = 18.3 watts of emitter consumption
  • Voltage sag may be not as much as I have estimated because you may have really good cell and they are 2P. So maybe 8 volts?
    • 7.8 V * 4.96 amps = 38.7 watts of cell output

Hopefully, someone more knowledgeable jumps in to help with the calculation.

EDIT: Some progress on the Mod has been added to Post 8.

EDIT2: Another thing that got past me. You said you measured current to one emitter. I would expect current to take the path of least resistance and flow more heavily through the emitters that were not inline with the DMM. If I'm correct about that, your efficiency is probably higher than I calculated above.

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Hi all

I’m new to this forum and found this post while searching for the LED lights I want to use from some bike lights for another project.
The lights I have are HND-X3-V2 these come with the driver but for my project I would like a smaller driver with a switch (ideally still with the light indicator for battery life). Is there something out there. Plus if I wanted to by just these led lights and the driver where can I get them from?