Ultrafire WF-502b CREE just flashing

Hi, I'm new here... I bought a Fenix PD30 a little while ago and haven't been able to stop. Since then I've ordered three other lights, two of which are the Ultrafire WF-502b (one CREE and one UV LED). My 18650s are charging, so I tried to used two CR123s. They work fine in the UV light, but the CREE one just flashes (very) briefly every time the button is pressed. Any help here? These are the same CR123s that work fine in the UV...

Are you sure the non-UV light is designed for 2xCR123 voltage? it might be an 18650 only module. If its this one... you're lucky it doesn't

sku.16516

If you swap modules / hosts around does the discrepancy follow the module or the host?

I guess you were right, I popped in the 18650 and nothing, but then I realized that it was due to the lack of a protrusion on the battery (all protected 18650s are like this I gather?). So I decided to slip a dead button cell battery into the bottom to complete the circuit, and it works now. But I'm a little peeved about the 18650's flatness.
I guess these are things I'll get used to?

magician13134 said:

I guess you were right, I popped in the 18650 and nothing, but then I realized that it was due to the lack of a protrusion on the battery (all protected 18650s are like this I gather?). So I decided to slip a dead button cell battery into the bottom to complete the circuit, and it works now. But I'm a little peeved about the 18650's flatness.
I guess these are things I'll get used to?

Click to expand...

yeah many 18650 cells are like that. Their primarily used in PC laptops. Flashaholics account for very little volume. These packs are assembled / laser welded together, so there is no need for the "tip". All but 2 of my 18650 cells are flat topped like that.

That flashlight should have springs at both ends to contact the ends of the cell.

It doesn't... In fact, there's almost NO metal whatsoever (less than my UV one even). Is there any way I can get to that part to solder my own spring on? I can't seem to figure out how to take that part out....

There should be a small spring there, right in the center of the module... you can see it on the DX picture.

A spring similar to this is what you want.

http://theledguy.chainreactionweb.com/product_info.php?products_id=603

Assuming its .65" base will fit. You might want to order a few and cut/bend them to size. I did something similar on one of my modules.

Ok, well there IS a spring like that on my module, but it never touches the battery, there's a metal divider type thing between them. I can get some pictures tomorrow...

magician13134 said:

Ok, well there IS a spring like that on my module, but it never touches the battery, there's a metal divider type thing between them. I can get some pictures tomorrow...

Click to expand...

Huh? The spring should just hang down in the center of the battery tube.

Well... It doesn't. There's a small hole with a little metal ring in it. The spring never makes it to where the battery is... I could drill that part out, though?
Just to be sure, we're both talking about the light bulb end of the body tube, right? Not the other end? Because that spring DOES go into the battery tube

I think you should take a picture, because what you are saying makes no sense. When you take the head (containing the module) and tailcap off, the battery tube is just that, a tube, with smooth walls and no protrusions inside.

Right, it's a tube, but only one end is open (the back end). The other (front, light end) only has a little metal connector, so the spring can't fit through

Sounds like it's not fully taken apart. There should be 5 major components when the light is taken apart.

Two parts to the head, the module, the body, and the tailcap.

Sorry for the low-res shots!

Battery tube on the left, module(?) on the right

Same thing...

Battery tube with the module end pointing forward

That little metal circle is just that, there's no spring on the inside, in fact hardly any metal continues on inside...

Looks almost like some lathe/anodizing tooling left inside. Does it look wedged in?

Both of my lights have it... Wow, yeah they did just pop out. Thanks...

magician13134 said:

Click to expand...

It looks like there is some sort of a "wall" or divider between the light module and battery, with a metal contact of some sort thats supposed to connect the "+" battery terminal with the "+" contact of the light module.

I've Never seen that before:thinking:.

The risk in what you are doing, is you are conducting the "+" voltage through the depleted button cell battery. If that battery were to shift and simultaneously touch the +battery to the inside wall of the light you'd have a dead short across the battery.

You should be aware that Lithium Ions are EXPLOSIVE, they can catch fire when shorted and vent toxic lithium gas. DEFINITELY not something you want to take lightly.

Looking at the inside parts of that light, I dont think adding a small spring to the module will help, since its the battery+ contact you need to make with that divider wall.

lighthound sells small neodymium magnets, sized similar to a small button cell. I have seen guys place the magnet on the battery+ terminal and use a small dab of super glue to secure it. That way you will have the "nub" where its supposed to be.

magician13134 said:

Both of my lights have it... Wow, yeah they did just pop out. Thanks...

Click to expand...

what!!??? oh man, now my head is spinning

They left part of the anodize tooling inside the light?

I gotta see this... take some more pics of the light module, that piece and whatever close ups you can of the individual pieces. camera phone pics will do.

thats bazare.

I wonder if all 502 series superfire/trustfires are like this?

The body of the light should just be a hollow tube... at least thats the ONLY design I have ever seen used to host a P60.

There is nothing wrong.

The spacer with a metal stud in it is a standard feature of all WF-501Bs (and A, C and D for that matter).

All you need is a button-topped 18650 cell rather than a flat top.

Please don't use a dead battery as a contact; that is inviting disaster.

You can remove the spacer - it will push out, but I really don't recomend it - it is put there to keep the comparatively soft springs centred and not slip off to the side where they can cause a short circuit.

Just buying the right battery will fix it.

lctorana said:

There is nothing wrong.

The spacer with a metal stud in it is a standard feature of all WF-501Bs (and A, C and D for that matter).

All you need is a button-topped 18650 cell rather than a flat top.

Please don't use a dead battery as a contact; that is inviting disaster.

You can remove the spacer - it will push out, but I really don't recomend it - it is put there to keep the comparatively soft springs centred and not slip off to the side where they can cause a short circuit.

Just buying the right battery will fix it.

Click to expand...

I agree.
Just order some AW cells. They are top quality and have the nib on the end.

Ha ha... Well they're out and I don't think they'll go back in. (The metal piece in the middle snapped when taking them out, but both lights work fine now.
And the reason I wasn't too concerned about shorting is that the was also a grove, I guess for the immaginary + terminal were the button cell got wedged, but no worries, it's not necessary any more. So just to clarify, I took out a piece that WAS supposed to be there. I wasn't actually too impressed by this light (bigger and not as bright as my PD30, not to mention, the odd mode of turning on) so I was thinking of selling it. This is something now that I would need to point out on an eBay auction right? "Brand new, except... I took out a piece that is broken now". Oh well, they seem to work fine. I guess these are things I'll learn, because I'm sure I'll be buying PLENTY more soon...