Using DX C30 with extension tube with 18650?

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Haggai
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Using DX C30 with extension tube with 18650?

Can I use the DX C30 flashlight (uses 3xAAA) with a 18650 if I get an extension tube?

The voltage is ok, but I think it's direct driven - how will it react to the stronger battery? Is it only a matter of (much) longer runtime?

Budgeteer
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If purely direct drive that will be no good... i would advise against it.

kragmutt wrote:

They're gonna send you a green redcat with a black LED.

Haggai
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Too much current?

But how does it handle current with the 3xAAA? Just pulls as much as it can?

I never saw it pull more than 450mA, is this the limit of AAA?

Match
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I've gotten almost 1.6amps out of a 3xAAA setup, so the batteries are not the limit.  

About the C30, I don't know if an extension tube is readily availabe.  May just be better off getting an x2000 - which is the same light, only a bit longer (and with ribs inside to keep the 18650 centered).

Haggai
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There's this: http://cgi.ebay.com/NEW-EXTENSION-RING-RECHARGEABLE-18650-BATTERY-/160544647867?pt=US_Flashlights&hash=item256134eabb#ht_2871wt_1102

 

If the batteries aren't the limit, then what is?

Maybe a resistor?

I'll just have to disassemble the light, I guess...

Don
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Match wrote:

I've gotten almost 1.6amps out of a 3xAAA setup, so the batteries are not the limit.  

About the C30, I don't know if an extension tube is readily availabe.  May just be better off getting an x2000 - which is the same light, only a bit longer (and with ribs inside to keep the 18650 centered).

 

I have/had an X2000 from DX.

Avoid!

 

It is junk.

It now produces no light but pulls 8 amps from an 18650 and smells very, very bad.

No abuse, just a crap light. It killed itself without any provocation. 

 

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

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

UDO
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I am direct driving c30 from 14500 li ion... No problems so far. It puls 1,4A, gets hot, but not too hot. Runtime is a problem, so I will get this extension to use with 18650 (thx for the link!)   

Haggai
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Hmm, I found this: http://www.dealextreme.com/forums/Forums.dx/Forum.18697~threadid.321792

Looks like before the mod the LED was direct driven with no resistor, right?

 

And Don, thanks for the warning.

Looks like I can't get triple the runtime with a 3$ upgrade. :/

Hobbyfotograaf
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3x AAA alkaline (fresh out of the packge) = 4,8V, but the internal resistance of those batteries is higher than the resistance  of a 18650 lithium-ion cell. So the current could be a little higher on a 4,2V 18650 cell, but i don't think that will destroy the led.

I have done some tests with this 3x AAA bike-light, modified with a XR-E R2 led: http://www.dealextreme.com/p/3w-60-lumen-2-mode-front-white-light-with-mount-for-bike-black-silver-3-aaa-47705 . With a 14500 cell it is just as bright as with 3x AAA Nimh cells. But the 14500 dous not fit without rolling some thick paper around it (it was just for testing).

If there was a lithium-ion cell with a diameter of 21-22mm and 52mm length, it would fit in the battery tube. A protected 21500 schould be perfect to replace the 3 AAA cells (with the protection circuit it will be a bit longer than 50mm).

Haggai
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I disassembled the pill - it is indeed purely direct driven.

Connected to an empty circuit board (only + and - connections) with no resistors.

Ah, well, was a nice idea.

I hope it works for you, UDO!

UDO
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I think it works because thin wires to the led somehow limit current enough so that led doesnt blow Wink 

Haggai
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Maybe. Smile

 

But just for fun - if I wanted to add a driver - would it then be safe to use 18650?

What driver would you suggest for this light?

ledoman
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Haggai wrote:
But just for fun - if I wanted to add a driver - would it then be safe to use 18650?

What driver would you suggest for this light?

It was my first mod. I've used driver from DX Sku.7612 but you can use also Sku.6190. No problem to use 18650 with those.

But if you make sum of ext. ring and driver costs, you are allready over half of the price for a new 18650 zooming one. 

Haggai
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Yeah, but just for fun Smile

And thanks for the suggestions.

Isn't 1000mA the upper limit of XR-E? Shouldn't I choose a driver with less output than that at high?

Don
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Haggai wrote:

Yeah, but just for fun Smile

And thanks for the suggestions.

Isn't 1000mA the upper limit of XR-E? Shouldn't I choose a driver with less output than that at high?

 

At least in theory. Many people have driven XR-E's at up to 1400mA though it will not last as long at that current. Heatsinking is imperative for you to be able to drive them hard.

 

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

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

Haggai
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Well, there's hardly any heat sinking in the C30.

It's just a hollow aluminium pill with very thin edges, and the empty circuit board and led star constitute its bases (air between them).

I don't think I should drive the LED at any more than 700mA (which should be plenty bright for my needs - with the current 300-400 mA it draws now it is bright enough).

I just wanted to use the 18650 to gain more run time, not more brightness (but that's a bonus, obviously).

Don
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The internal resistance of an 18650 is very, very much lower than that from 3 AAA cells in series, so current will be a lot higher.

So if you don't add a driver you will have to add some resistance. I'd start thinking around 2 ohms - start with 5 and measure the current.

Or add a driver.

 

If you are happy with the current brightness, I'd go for a 350-500mA driver - you get the same output and 5-7 hours runtime.

 

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

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

Haggai
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I was thinking about a resistor, but I think I want to be able to also use the flashlight with the 3xAAA option.

I guess a resistor will make the current much lower in this case?

Is there a suitable driver for this?

 

[I should really have openned this thread in the modding subforum...]

Don
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It ought to be possible to bodge a resistor in somewhere that it can be removed when required. Or turn it into a twisty and use some quantum tunnelling material between a couple of bits of metal as a switch. The stuff is cheap.

 

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

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

Don
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Be-Seen Triker wrote:

You're serious, Don?  You think the battery holder at an amp will loose 0.3v in the 3xAAA configuration compared to the max 4.2V of a single 18650?  In all my time in electronics, I have -never- seen that much loss even with the worst connections.  Anything close to this would simply open rather than sustain that level of impedance.  Besides, how long will that 18650 really hold 4.2v?  It is, after all, a 3.7V cell fomr most of it's useful charge.  That flashlight is designed for 18650 cells.  I wouldn't do anything but extend the body.  Just don't accidentally put in 2xCR123A's.  That would be disasterous.

 

I doubt even good AAAs can sustain 2A for any length of time, even the worst 18650 shouldn't even break sweat. If the light is designed to limit current depending on the internal resistance of the cells, lowering the resistance of the cells will inevitably raise current. All cells sag under load - alkaline AAAs sag hard - 18650s sag a lot less - so you have at least as many volts and more amps.

 

I'll try this with a Solarforce L2i which can use both.

With a Solarforce 0.9-4.2V single mode dropin.

Three LSD AAAs, 4.264V output on lightbox and current

1080 lux & 940mA

 

18650, 4.189V output on lightbox and current

1402 lux & 1620mA 

 

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

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

Don
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That's what is coming out of the cells. Emitter draw is harder to measure and requires soldering before and afterwards. 1600mA is almost certainly losing a fair bit as heat. 4.2V is well past the Vf of the LED so I suspect the driver is dumping quite a bit of that as heat. You'd need to ask one of the guys round here who knows about electronics about that - my knowledge could be printed out and comfortably inserted into my eye.

 

The OP light says the emitter is a Cree P4 so around 1000mA Cree spec but you should get away with 1200mA in short bursts without cooking the LED. 1400 if you have really good heat sinking.

 

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

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

Haggai
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So if I take the resistor approach - I guess we're talking about at least 2W resistor? Preferably 3W I guess.

If I know the internal resistance of the battery / battery pack - can I calculate the current I'll get through the resistor? If so, I may be able to pick a resistor such that it will work well with both battery configurations.

Couldn't find a suitable driver, though I searched qutie a bit. Seems that drivers whose max output is below 1A are taking only 1.5V input, but maybe I missed something.

Haggai
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I just got the extension ring I linked to above.

It doesn't fit the C30 - the threads diameters don't match Sad

Ah, well, another 1.56$ lost in the pursuit of the perfect torch Smile

UDO
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Well, yesterday I bought this extension ring too Sad  How much is the difference in diameter? It doesnt fit even if you use forceLaughing?

Haggai
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It's too small, not too big.

Maybe you could use some conductive metal sheet as spacer, but it won't be nice and I doubt that replacing the batteries would be fun.

I guess you could solder it to the C30 tube, but then you'll only have 18650 and not 3xAAA.

UDO
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Got some great news for you Haggai Cool I received the extension ring and like yours it doesnt fit... BUT I was so frustrated to fit an 18650 into c30 that I figured it out! 18650 fits C30 without extension ring! You just have to remove the tailcap spring and unscrew the ring that holds the switch. Now you have almost 1 cm more space and 18650 fits without a problem! Just try it! And to make things even better (at least for me Tongue out) the extension ring fits onto another 3xAAA light that I got. 

I really love my C30 now - its really small for a 18650 light - a whole 1 cm smaller than already quite small Trustfire TR-801 + its a zoomable light. Now if I could only somehow fit a QTC pill in it and it would be a perfect light for me. The led did turn a little blue (from 6 months on 14500 DD), but with QTC and improved heat transfer (thermal grease) I dont think it would be a problem anymore. Size comparison: 

c30 with 18650

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I was wondering where you guys got the extention ring  and after hearing it doesn't fit ....ah .. never mind ...:~

I like my c30 if that is even what it really is ?? ..I have no idea what emitter is even in it but it's pretty warm and it's a 3 mode ..I still  think it's a great light partially because of the tint ..maybe also because it was my first real led light

       καὶ τὸ φῶς ἐν τῇ σκοτίᾳ φαίνει καὶ ἡ σκοτία αὐτὸ οὐ κατέλαβεν

                            

       Dc-fix diffuser film  >…  http://budgetlightforum.com/node/42208

Haggai
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UDO, that's great news indeed! Smile

I'll certainly try it today when I get home.

UDO
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I think I am going to buy some more of this c30 like flashlights now - they are very cheap here - 4,9$: http://www.buyincoins.com/details/zoom-focus-3-mode-aaa-cree-led-flashlight-camping-light-product-2780.html + they are 3-mode + you can get -15% from that price with code  (10%eBay110 and Recommender = nissius). I know that probably I wont get a cree emiter, but just because of the price and possible 18650 mod this seems a really good deal. Did anyone already bought this flashlight from Buyincoins? Is it any good?

Haggai
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Dirt cheap, but they have this annoying red ring at the head.

For 1$ more you can get one without the ring: http://cgi.ebay.com/Adjustable-Zoom-Focus-LED-Flashlight-camping-torch-LC3-/220741014541?pt=US_Flashlights&hash=item336530940d#ht_4483wt_1142 .

ledoman
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It's not Cree Q5 but Osram Golden dragon instead. At least a batch from a month ago was that. I've made complain and they say I either return item or partial refund about 1/3 of a price.

I can send you one if you want. More on PM.....

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