Spec me an LED Torch

Selekt0r said:
I've shimmed the drop-in with some aluminium from a coke can which is the best I can do for now until I get some copper sheet ordered. Hopefully that will manage to help with the heat dissipation for now, although I don't plan on driving it too hard/long.
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That's what I did, well, I shimmed the torch. I also applied some thermal compound to the torch before placing the shim in place. The applied a small amount of thermal compound around the dropin. The whole torch heats up when its set to high for a long period, so It must be working.

DSC_1598.jpg


Took 2 layers to get a snug fit. Copper would be even better i'd imagine.
 
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Aod said:
Okay, it looks like the AK437 has 2x 6V 4000mAh lead-acid cells and a runtime of 30 mins.

roughly this implies that it's a 12v 100W halogen bulb. Wiki tells me that high-power halogens produce around 24 lumens per watt which means that this light would produce something like 2300 lumens when freshly charged, and that would taper off rapidly as the batteries are discharged.

The BC40 is rated for about 700 lumens afaik, so about 1/3rd the brightness, but the BC40 only draws about 9W of electrical power and is considerably smaller :)

I hope this helps :)
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Thanks for taking the time to look into it. :)

I was curious as I just bought a BC40 thanks to mrk's comments and my brother has one very similar to the AK437 but as you say ..."Poor runtimes, very heavy, beam-pattern like a pizza, inconsistent brighness during the runtime", all that is true.

I tried testing my brothers recently but the batteries don't even charge up anymore and from what I know he hasn't used it much.
 
2011-10-29-15.07.jpg


Just doing a little bit of Science! to see how long the 2400 UltraFire batteries last at max brightness on the BC40 and the laptop salvaged batteries in the C8 at max as well.

Before starting the Ultrafire batts read: 4.11 and 4.2 volts while the laptop battery read 4.07. The laptop ones are of unknown mAh, is there any way to find out what their capacity is?

JetBeam say the BC40 will run for 1.5hrs at max and 11 hours at low but they don't say what capacity battery was tested for those figures, is there a standard capacity they use?

If these UltraFires last longer than 1.5 hours then the Yezl batts will last even longer. Happy days :D

I'll not run them down completely of course, after 1 hour has elapsed I'll turn them off and take a reading from the batteries and then I can estimate approx run time.
 
mrk said:
I'll not run them down completely of course, after 1 hour has elapsed I'll turn them off and take a reading from the batteries and then I can estimate approx run time.
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I'd be interested in the formula(e) / method to do this run time calculation from the voltages, since I want to treat my new cells 'nicely'.
 
Calculations? Formulas?


!!!


I was just going to apply some layman's mathematics to the results to extimate run time :p

I have one set of results now, running the 2nd battery pair and will post shortly :)
 
Right. I have been away the last week, so if i can continue from where i left off.....

Just before i went i saw the links to the two super cheap torches on the bay...

chrisxuk said:
http://www.ebay.co.uk/itm/UltraFire...Flashlights&hash=item415e194815#ht_500wt_1287

Also, the eBay listing says it's:
Powered by 1*18650 battery 3.6/3.7V
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Nick1881 said:
What's the chances of this being any good?

http://www.ebay.co.uk/itm/ZOOMABLE-...itu=UCC&otn=5&ps=63&clkid=3664850990677912781
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So i figured what hte hell and ordered them both. :)

Now i need a decent 18650 battery and charger.

Bennie-Mac said:
Manafont or ebay, wherevers cheapest really :) There are a couple of UK places selling them for £15.99ish if you cant wait for delivery though.

Edit - Actually this place does them for £15.95 with free delivery, only a couple of quid more than the HK ebay lot.
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Anyone know where i can get the WP2 II from a UK store?

Also a recommendation on a battery or two for the Ultrafire would be great.

Thanks. :)
 
AW 18650s if you don't mind spending £15~ a battery, Aod recommends them and they seem to be the best of the 18650s you can buy so the price reflects that, otherwise Yezl 2400mAh ones posted about above are very good too and cost about £11 a pair.

The UltraFire 2400s are good but you need to make sure you're getting genuine ones because too many places sell fake ones. Genuine ones will have Ultrafire printed on the underside of them on the negative terminal itself.
 
mrk said:
2011-10-29-15.07.jpg
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i'm loving my bc40 too!

looking forward to the results though no doubt jetbeam would be using high end batteries for their tests.

i'm using genuine trustfire 2400 18650's...they come recomended via budget light forums and i got for $10.89 delivered for 2 and have good reviews

http://www.manafont.com/product_inf...h-rechargeable-batteries-flame-2pcsset-p-5560

in fact i will undertake a similar test with these trustfires at 830lumen

i have some questions about li-po batteries

1. when fully charged and not used how long do they hold their charge for before needing to be re-charged?

2. is it ok to re-charge them when part used or do they need to be run down before charging.

3. once charged can they be used instantly or should they be left for a time before using.

hope these questions made sense :p
 
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ThriceNightly said:
in fact i will undertake a similar test with these trustfires at 830lumen
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I'm not sure if I'm testing it all wrong but if you could try replicating my results below that would be awesome.

My pair of laptop stripped batteries are charging and they're the last pair I have left to test in the BC40 but so far I have found that the BC40 will shut off after exactly 1hr 15mins on the 2400mAh protected Yezl and UltraFire batteries. I took a voltage reading before and after of each cell. On the BC40 one cell completely goes down, voltmeter can't even get .1v from it while the other cell gets a stable reading (results below). Combined they output 1.32v~ so I imagine this is why the BC40 shuts down after 1hr 15mins because the 2 batts cannot give enough juice for it to light up due to one being dead.

The UltraFire C8 continues on after 1hr 15mins though and I took a reading anyway after that time (results below) so I can only estimate that the C8 will continue to shine for a good few hours at max brightness. I would have tested the SolarForce L2 with XM-L but SF have not sent me the replacement tailcap yet :/

Anyway, results so far are:

voltages.png


I will update the laptop stripped battery results once it finishes :)
 
^ Any idea why their would be such a huge difference in after voltage of the two cells? I wouldnt have thought that such a small difference in starting voltages would reduce the runtimes so severely. Perhaps its drawing more power from a certain cell somehow?

I tried to test the battery runtime on my TK21, however it seems to automatically lower the brightness level when the battery is getting low. Handy i guess but annoying for testing!
 
Maybe so but it's 15 minutes off the JeatBeam quoted max runtime at 830 lumens so it's within spec. I can only imagine it's as ThriceNightly says, that JetBeam used higher capacity cells for their tests. Seems strange that one battery would be completely dead though instead of both being used evenly!

We'll know if that's how it's been designed if ThriceNightly can replicate the same results I guess. Maybe it's been engineered that way due to the power the torch pulls?


Edit*

I just got this email in a mailshot from 7dayshop:
http://www.7dayshop.com/catalog/pro...d=112873&PHPSESSID=i5jllm8suve9vj107930u9dh56

Look at it, 1000 lumens yet look at the price tag and the beam range!

It's the brand itself that the asking price is mostly paying for :/

It's not even water or shock proof! For over £100 less you could get a HID Xenon powered torch!
 
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I am not sure but will confirm which one runs dead once the laptop stripped batts finish charging and I do the test on those :p

I don't thijnk it is heat because the torch was getting constant cool air from the fan at all times. Since both battery pairs from 2 different brands saw the same affect in the exact same time it does appear to be by design. If it happens on the 3rd battery pair (the laptop ones) then that pretty much confirms it I guess.

Edit*
Damn, that uf-980l looks good, should I buy? Hmmmmm! What is the run time on medium? I won't even ask about high because it gets to 60 degrees within minutes!
 
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mrk said:
I just got this email in a mailshot from 7dayshop:
http://www.7dayshop.com/catalog/pro...d=112873&PHPSESSID=i5jllm8suve9vj107930u9dh56
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Oh dear! I'm still torch hunting but it won't be that. Splash proof? What use is a torch you can't use in a passing rain shower? :/

Mind you, they've got a 6D Maglite next to it. I know those things all too well being a 4D owner. They should be considered offensive weapons because they're not good for much else. :p

Edit - Just seen the P14 a few pages back. It'll happily use my Eneloops which is a good thing, so reckon that'll do once the card has recovered from recent shock! :eek:
 
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damn i accidently switched the bc40 off for 1 minute during the test but turned it back on. the torch automatically shut off at 1 hour 37min.

say 1hr35 with my accidental switch off

the torch was very hot to touch but just disemblimg it now and both batteries are warm not boiling as i expected......unfortunatley i cannot find my multimeter :(

will try this test again on another fresh charged set of trustfires but i won't switch off this time :)
 
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Cheers! Hopefully you can find a multimeter and test the batts, or could you try both batts in the UltraFire and see which one is dead that way?
At least that would confirm if one is dead while the other isn't and thus confirming it's by design!
 
unfortunatley mrk the multimeter has been missing for a while :p

have tried the used batteries in the uf980l. they are both still working albeit on lower power than usual and one is dimmer than the other....so neither have fully discharged?.

the circuitry is obviously a bit more advanced in the bc40.

will see if i can get close to 1hr 35min again without switching off this time.
 
Ah cool, I'm currently 13mins into the laptop 18650s now so once they finish I will try them both in the Ultrafire C8 which should tell me if they both have some charge or only one. Then update the results table above.
 
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