Convoy L4 Problem

I have a problem with my recently purchased L4.

I put in an old battery measuring 3.6v and the light works fine. I put in a fresh charged battery showing 4.18v and the light flashes once when turned on and then it goes off. Won’t turn on again. Polarity is correct. Then when I put in the 3.6 battery it works ok. After this I’ll put the 4.18 back in and it will turn on to one medium mode, but when it turns off it won’t go on again. The 4.2 battery works in my other 1x18650 torch.

What’s going on?

Are both batteries the same length? Is the fully charged battery tight when closing the tailcap?

Yes identical batteries. It is tight with no room to shake or bounce. Spring is firmly pushed against terminal when screwing cap on. Same battery worked in this light prior to charging. I don’t think charging could’ve ruined the battery though as it still works in another light

I was thinking one of the batteries was shorting out because it was too long,

The 4.18V behaviour sounds just like what happens when a cell runs out and the light can barely light.

Hmm yes so what’s the problem exactly? The cell itself is running fine in another torch without issue.

any photos of your battery?

Battery is probably too snug and shorting accross the driver.

Is it protected battery? Maybe it trips the protection circuit when trying to pull too much current (for the circuit) from fresh cell?


Here we go. Yes it is protected. Hmm… is that the problem? It’s a Trustfire protected cell. Yes i know xfire = crapfire. I bought these before knowing what good cells are!

Blue ultrafire battery??

If so, that might be your problem.

Dammit. I’m sorry to everyone who assumed I was running quality batteries. That must be the cause then.

So cheapish protected good capacity cell that can handle the torch I was thinking ICR18650 26F Pink 2600 Protected
Will that do? Jees I feel stupid haha.

It says protected, but it’s Ultrafire blue. It is likely even less protected than an unprotected cell…

The issue may be with the tailcap. Make sure you tighten it down as it may have loosened.

Those Samsung will work great.

Lol, I think that blue ultrafire battery might be your problem, or the tailcap as unknown stated.

Aoeu, I just tried my L4 with 5 different batteries, all fully charged, and they all work perfect. I tried Panasonic Protected NCR18650B, Trustfire Flame Protected 5000, Samsung ICR18650-28A flat top, and two other flat top brands I had, and they all worked perfectly in the L4.

Also, about your button issue you posted about earlier, I tested both buttons, the rear power button and side mode button. I find the buttons have a "soft" press of lead-way before the button actually changes modes or powers off. Both my buttons are like this.It doesn't have a "loose" feel to me, but a very softness feel, if that makes sense.

Personally, I actually love the way the rear and side button on my L4 feel. They are very soft to press, and not hard and stiff like so many other flashlights I have.

Well you know at the time my reasoning was “Oh 13 positive reviews on DealExtreme it must be a great battery I’m sure these guys know what they’re buying. I’ll buy one too!” And so they worked just fine in my TR-3T6 for 2 years now so I figured they were “good” batteries. But you know there’s always gonna be something that can make something good seem relatively crap.

My tail cap button is annoying actually. WHen it’s in the on position there’s a little air bubble under the rubber. That’s like when you use machinery and the switch is covered in thick rubber bubble so it’s water-resistant. Only problem from that is that when you use gloves to turn the machine off you have to mash the button! Ok so the flashlight isn’t as bad but it’s what I think when I use it!

I’m going to try to tighten down this switch though because it might have something to do with it also. And also buy a floodier reflector. I was just too excited by demigod’s post about the L4 bargain to think about the beam pattern which I dislike! And buy some GOOD batteries.

Most embarrassing “my torch won’t work” question ever. Worse than reversed polarity. hahaha

What tint did you get? My L4 has an amazing amount of flood (not a super-flooder though) and super bright hotspot. I got the XM-L2 U2 1A, and I am in love with my L4. I'm not sure how much floodier you can get, without going SRK type flood, which is a different animal altogether.

I just tried to on and off my L4 with some "super thick" leather cowhide gloves, and have no problem turning on and off the flashlight at all. Maybe yours might be defective somewhat, Idk. I do feel the little "air bubble" you mention when on, but that is the nature of the beast so to speak, as it has momentary function as well. And the air bubble is only about I would guess 2mm-4mm so for me, I don't see anything wrong with it.

Either you got a dud, or maybe the L4 is just not of your liking I find it hard for most people to "not" like the L4, especially after I received mine. After playing with it for the last 6 days, it has become one of my favorite lights.

My biggest complaint with the L4, is that I'm just trying to find a stainless steel tailcap that can fit on it to match the stainless steel bezel I have coming!

demi I think you are blinded by love lol. The gap in the cap isn’t that bad but it’s not something I’m accustomed to. I generally don’t like freeplay in things, I prefer to have everything adjusted without freeplay. I got the 4C tint because someone said it looks more ‘natural’ and well I’m not so sure I like the tint. I think I prefer something a touch more white and less yellow, but really I haven’t had a chance to get this torch outside because somebody bought shit batteries………….

Am I missing something here? I keep shopping for protected batteries under the belief they’re safer. Can’t I just buy unprotected and let the torch shut itself off when it’s low, and then the charger stop charging at 4.2? Or do I sound too stupid on this topic to risk with unprotected? I suppose protected is just easier……

There are components on the battery side of that driver. There may still be a bridging problem. Try covering them with some tape to make sure.

No, I'm not blinded by love! Haha, I hate yellow light, which is why I stuck to the safe U2 1A! Seeing yellow in my lights always reminds me of my old Maglite growing up as a child. It's the same when I see cars with yellowish headlights. My Maxima has Xenon's (HID), and I will never go back to old school lights ever again. Maybe time for you to mod with the LED of your choice. You can also change out the tailcap to a different clicky I'm pretty sure.

As for batteries, it really doesn't matter if you choose run protected or unprotected in this light, or most flashlights nowadays, as most flashlights have a low voltage cutoff. Plus, if you use an unprotected battery, you will know when it's running low, as the light will start cutting out usually (but you can keep running the light), which just means its time to charge it up! With protected batteries, the light just shuts off completely, with no warning. So it doesn't really matter which battery you choose, as long as its a good quality cell.

Well this is frustrating. I’ve again tested an identical cell (brand, capacity, same batch purchase, physical size) @ 3.6v and it works in this light. The 4.2 is not happy. Flashes once when switch is pressed. So perhaps it may not be the battery shorting the driver circuit area. However close inspection shows the spring may be bridging this resistor/square thing. Would this still work on a lower voltage battery but not the higher one? Perhaps. Not able to bend this out of the way right now. Interesting though.

Thanks for that demigod, I’m just gonna buy unprotected now. I don’t know why I haven’t before. It just seemed so much safer and foolproof.

Anyway checkout that resistor under the spring there. It appears it is touching the northern side of the resistor for certain, but the southern side I can’t see exactly. It looks like a very minute gap if anything. 1/10th mm perhaps.