Author Topic: LED flashlight  (Read 5240 times)

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Offline Srbel

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LED flashlight
« on: December 06, 2015, 12:54:11 pm »
I have bought it on eBay cheaply. The aluminium case itself is worth more than what I have paid. It allegedly has a CREE XM-L T6 LED. They claimed it has up to 2.000 lm, although datasheet for that LED says 1050 lm max. I knew it was bollocks, and I expected to get like 500 lm from some Chinese LED. But, the problem is that I got what it seems a faulty LED. It has multiple LED strings in the single package, but only the outer strings seem to work. So, maybe it is a genuine CREE, but a factory reject.

It is similar to this one: http://www.ebay.com/itm/3000lm-WF-502B-CREE-XM-L-T6-LED-Flashlight-18650-Torch-Bicycle-Lamp-5-mode-/351593571726?hash=item51dc9c258e:g:Me8AAOSwnH1WXZaT



You can see that, when zoomed-out (narrow beam), the LED is square and lighten up completely.

But, this is how my LED looks like:



So, I want to change the LED. But, in my country, the similar one costs almost 15 euros!

I could buy CREE one on Farnell, wait for a month, then pay customs fee, taxes, 10% to the company who buys it for me of Farnell, and 2 euros local shipping. But it is not worth it.

I could buy it on eBay cheaply, no customs fee, no taxes, no 10% charge, no local shipping, but I would get either a counterfeit LED or a genuine factory reject. Both of which might be better than the LED I already have. The one I have is too weak.

So, any recommendations?
 

Offline amyk

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Re: LED flashlight
« Reply #1 on: December 06, 2015, 04:19:44 pm »
You spell it "aluminium" but also call that a "flashlight" instead of "torch"?

Try your luck with eBay if you think buying from Farnell is too expensive...

 

Offline Srbel

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Re: LED flashlight
« Reply #2 on: December 06, 2015, 04:34:36 pm »
You spell it "aluminium" but also call that a "flashlight" instead of "torch"?

Meaning what?

Try your luck with eBay if you think buying from Farnell is too expensive...

I earn 14,5 euros a day, and loose 11,5 hours a day doing it. So yes, it is expensive.
 

Offline Mechanical Menace

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Re: LED flashlight
« Reply #3 on: December 06, 2015, 05:15:14 pm »
You spell it "aluminium" but also call that a "flashlight" instead of "torch"?

To be fair "aluminium" is the official spelling that even the US agreed to to get some other elements get Americas preferred names according to IUPAC. And British and US spellings are both acceptable in Britain and the USA, the only guideline on that is to be consistent in certain places. Mixing "normalise" and "aluminum" is a OK but not "rationalize" and "sanitise..."
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Offline Bob F.

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Re: LED flashlight
« Reply #4 on: December 06, 2015, 05:33:49 pm »
As you bought it on ebay tell the seller you want a refund or replacement - it may be a genuine mistake/dodgy part and they may want to retain their ebay rating.  If they start  to mess you around, lodge a case with ebay/paypal immediately - almost certainly you will be refunded by ebay/paypal as long as you follow their rules.  Send all communication via ebay messaging - not private emails.
 

Offline Srbel

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Re: LED flashlight
« Reply #5 on: December 07, 2015, 08:02:12 am »
I've bought this lamp few months ago. It was not worth it to complain and to have to send it back (which would be expensive). For the money I paid, I felt that the case alone is worth it, so I left a positive reply to the seller.

I've used the lamp as-is. But now I just want to change the LED to get the full brightness. Now, what is the best solution for that? What can I expect to get if I buy the LED of eBay? 99% fake part? 99% factory reject?
Or try to get a free sample? But who would give me that? It is a 10W LED...

I haven't seen CREE offering free samples. :/
« Last Edit: December 07, 2015, 08:03:59 am by Srbel »
 

Offline Srbel

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Re: LED flashlight
« Reply #6 on: December 11, 2015, 09:16:30 am »
Nobody gives free samples?
 

Online Whales

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Re: LED flashlight
« Reply #7 on: December 11, 2015, 09:45:52 am »
Hey Srbl,

Indeed those lumens are bollocks :P  Welcome to the land of LED torch sellers.

I have several cheap (~7-8 AUD) torches in my house running some form of Cree-like LED.  I've only had to swap an LED out once in one and it was because I had destroyed the old one.  I learned that the lenses on the LEDs are made of a delicate gel, not a hard plastic or of glass.

The easiest repair would to buy another LED pre-soldered onto its mount/heatsink and swap that in.

 Unscrew the front of your torch and have a look at what style is installed -- commonly they look like stars:



Yours will have a couple of wires soldered to it.  The other ends of these go to a current limiting/control board, often mounted right below the LED.  Presumably this is working fine in your LED and you will only need to replace the LED. 

Sometimes the stars are obscured.  In one of my torches the star is fastened behind a piece of threaded aluminium:



Searches such as 'star led', 'star xm-l' and 'star-cree' work well on a site I can suggest: dx.com.  These can be had for less than $5 Australian (but note that whole torches can be had for a little more from this site). 

I've had a good experience with DX in every way except shipping time.  Their complaint ticket system works, they're cheap and for me they have free shipping.  There are still other caveats -- if you are buying batteries off dx for example, make sure you read the description well.  They're polite enough to give an 'actual capacity' figure but not enough to put the right numbers in the title.

EDIT: Flashlight community: http://www.candlepowerforums.com/vb/content.php  Useful info resource: http://flashlightwiki.com/Main_Page
« Last Edit: December 11, 2015, 09:52:36 am by Whales »
 

Offline senso

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Re: LED flashlight
« Reply #8 on: December 11, 2015, 10:00:45 am »
You should have opened a claim in eBay, they would refund you without sending it back.
 

Offline Srbel

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Re: LED flashlight
« Reply #9 on: December 11, 2015, 10:11:09 am »
@Whales

Thanks mate. DX has free shipping for my country too.

I will buy this one: http://www.dx.com/p/cree-xm-l-t6-10w-885lm-6300k-white-light-led-bulb-for-flashlight-black-3-0-3-5v-158753



P.S. When I opened the flashlight I have noticed that LED star PCB does not have good physical contact to the alumimium flashlight case, it is just wobbly. So no heatsinking. Plus, if that copper cover, that holds the LED in place, would be screwed down completely, it would shot the LED. Great design. I would have to modify that bit too...

You should have opened a claim in eBay, they would refund you without sending it back.

Refund would not fix my problem. Changing the LED would.
« Last Edit: December 11, 2015, 10:12:55 am by Srbel »
 

Online Whales

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Re: LED flashlight
« Reply #10 on: December 11, 2015, 10:08:36 pm »
It's common for the stars to be press-fit in.  Sometimes there is a little glue and in good lights they go to the effort of better contact.

Again be wary of the lumens stated by sellers: the actual amount you will achieve is determined by:
  • The model and binning of your LED (see here)
  • How much current you are using
  • How well the LED is being kept cool
  • How much of the light is being sent in the direction you want to measure (ie are the reflectors any good or is light lost into the body)
  • What the front window/lens is made of
The '885lm' of your seller is simply 'hey you can do this'.

Hopefully this works out for you.  DX shipping may have become faster since I last used it, but you might not have your LED until into next year.

Quote
Plus, if that copper cover, that holds the LED in place, would be screwed down completely, it would shot the LED
I have just had a look.  There is a plastic ring sitting between the star and the plate.  *phew*

Presumably not much heatsinking is achieved through this plate as the solder blobs on the star (and the plastic ring) would hold it too far away.  Most of the heatsinking would have to happen through the corners of the star into the body.  The plate on top just seems to hold the star in and against the body.
« Last Edit: December 11, 2015, 10:10:50 pm by Whales »
 

Offline Srbel

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Re: LED flashlight
« Reply #11 on: December 12, 2015, 09:21:05 am »
Well, it says 24 hours free delivery on that item. I have bought it yesterday afternoon, and they have shipped it today.

I meant that bottom part of the star has no good contact with the flashlight body. The copper plate is not pressing it against it at all, and there is no plastic insulator/spacer at all. So, no heat sinking and a risk of short-circuit.
 

Online Whales

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Re: LED flashlight
« Reply #12 on: December 12, 2015, 10:03:45 pm »
Well, it says 24 hours free delivery on that item. I have bought it yesterday afternoon, and they have shipped it today.

24 hours for them to dispatch it, not for the whole shipping process to complete and the item end up at your doorstep  :(


Offline ECEdesign

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Re: LED flashlight
« Reply #13 on: December 12, 2015, 11:43:24 pm »
If you really want some information on modding flashlights, head over to the Candle Power Forums (CPF).  They have lots of technical information over there, its pretty neat stuff.
 

Offline Srbel

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Re: LED flashlight
« Reply #14 on: December 14, 2015, 08:35:50 am »
Well, it says 24 hours free delivery on that item. I have bought it yesterday afternoon, and they have shipped it today.

24 hours for them to dispatch it, not for the whole shipping process to complete and the item end up at your doorstep  :(

Nice scam...
 

Offline PedroDaGr8

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Re: LED flashlight
« Reply #15 on: December 14, 2015, 02:21:54 pm »
Many of the cheaper "Cree" flashlights now are actually using LatticeBright LEDs. LatticeBright copied the style and model numbers of Cree LEDs in pretty much EVERY way but performance.

These both have the same model name:


Here is a big thread on it at BudgetLightForums:
http://budgetlightforum.com/node/41084?page=3
« Last Edit: December 14, 2015, 02:23:50 pm by PedroDaGr8 »
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Offline Srbel

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Re: LED flashlight
« Reply #16 on: January 27, 2016, 07:00:33 am »
LED finally arrived yesterday. I have swapped it in. Added thermal paste, and some plastic ring to hold LED in place when copper plate is screwed in (I hope it won't melt). Now it works great. All LED strings work. LED is bright. Heat is well dissipated (case gets worm after only a couple of minutes).

Now, I just need to measure the current form the battery, so I can know how long will it last on full brightness and one charge.
Battery is Panasonic 2.700 mAh lithium.

P.S. On the new LED, it says CREE on the aluminium PCB. On the old, defective one, it says Lattice Bright.
« Last Edit: January 27, 2016, 07:02:04 am by Srbel »
 


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