Convoy L4 Problem

LED Flashlights – General Info 18650 Flashlights
20

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.

21

I'd do as comfy suggests - cover it up with tape and see if the problem goes away.

22

That might be your problem, as mine is not touching the resistor, just on the edge of it. Do you have a soldering iron, to move the spring over a little?

23

Should check mine - that's wayyy too close, even the good one. Hopefully nothing got fried and permanently damaged, aoeu...

24

I’ll get an iron onto it tomorrow. Report back. Thanks guys. Guess I’m just unlucky. 3am here bedtime!

25

Mine has good clearance (bought from WB). Its got a different spring, the typical bronze spring used in most convoy lights. Its narrower.

My latest L4 is similar to my first Convoy L4. Spring picture here. Maybe the batch from BG, or some of it have used a spring that is not that well suited...

26

The base of that spring looks like it’s way too big compared to the solder pad? It looks like that’s why they had to “slide” the spring over, but then it can contact the resistor. Do you have a smaller spring that you can try to use?

27

Wow, that spring! Too narrow springs can bend over. Definitely needs some insulation over the surrounding components. If you can solder the spring in two opposing points would make it more secure than just one blob.

28

Take the L4 head, take the 18650 cell, place the battery positive on the spring and take a wire/paper clip etc and connect the negative pole of the battery to the threads or retaining ring in the head. Don’t apply pressure to the spring, just let the battery rest on it.

If the component is the issue then it should light up fine without compression on the spring.

29

My flashlight is working fine, but I guess I could put a smaller spring on it eventually, as it does seem way to big for that contact pad.

Aoeu on the other hand, his spring is right on top of his resistor! Maybe it could have shorted something on the circuit board?

30


I have two Convoy L4 lights. I got one last month directly from Simon’s Aliexpress store, and I got another today from Banggood.
The new Banggood version has the exact same wide base spring as shown in the picture. My older version from Aliexpress has a narrower base spring that does not extend beyond the solder pad area of the driver.

31

well… I have different kind of problem with this L4 I received from Banggood :Sp

32

My BangGood L4 has the same wide spring - looks exactly like TexasToasted pic. The spring looks like it touch's one end of the SMD. So, I removed the spring and checked -- the spring pad is connected to that end of the SMD, so it was ok. I'll still replace with a narrower "copper" type spring from FastTech. My WallBuys L4 is fine - already has the narrower copper looking spring.

33

I think that most members here, when saw that blue battery, were like:

:bigsmile:

34

Rewound the spring tighter, soldered back down. Doesn’t work with the 4.2 still. Does work with 3.6 batteries. Guess it’s just the Shitfire battery.

Also, the medium on this torch is only about 10% dimmer than High. But whatever!

35

smart idea of just winding the spring smaller. I will do the same!

36

Either that or flip it…that spring IS shorting out on that resistor…notice the solder pad for the spring…that spring is much too large for that solder point…looks almost like a 5.5mm spring that is on the Nanjg 105C

37

I thought about flipping it but then my button tops wouldn’t contact the other end and you would have to bend it to the middle anyway. I’m just gonna buy some better cells that actually have electrons inside. Or whatever it is that they have inside. Unicorn blood.

38

Just the same, test it with the tail cap removed by bridging the cell and body. I’d really like to know the results when contact is made without compressing the spring. If it is still the same, scrap the cell.

39

I’m gonna have to find some wire for that and get back to you. Just gently pressing in the body against the head with minimal spring compression and it’s the same thing, just a flash and its off .