I wish I had this light in my hand to look at. Very odd indeed. Could even be something like the emitter not being reflowed properly.
That should be enough information right there — the first 4 go on the LED side, and the next 1,2,3 or 4 are put on the spring side.
So since you see four of them on the spring side, you don’t necessarily need to pry the pill open.
If you do, be prepared to look hard and if possible take pictures of it, maybe you just have a bad solder join somewhere.
Can you tell us what color S2+ you bought? Sounds silly I know but the new green S2+ is the only one I know of that ships standard with 7135*3. The others all come standard with at least 4 unless you specifically order a lower powered light.
It is the blue s2+ version
Sorry if i can't give you complete details now. (still at work). Will upload later pics of the light, beamshot comparison to my other lights, and readings using thick wire gauges. I believe this convoy is real due to good springs and led and also never heard of a fake convoy from banggood.
Google wants to help, and finds Convoy Flashlights
but that was six months ago. More info in that thread. Not saying that you got a fake, seems more likely it’s a bad solder join inside there, is my guess.
A fake convoy is of no concern here. A flashlight is just an aluminum tube. This problem is electrical. Something is limiting the current. Driver- wires - Led.
Improperly soldered LED or AMC chips? That would mean four or five chips aren’t soldered correctly, so I’d start by putting my odds on a poorly soldered LED, which is not uncommon. Is it on an aluminum star? Is there any thermal grease?
Let’s not forget the switch. It could be faulty.
So i tried my second convoy, bummer, won't turn on. Tried the other tailcap and it now turns on. So the second convoy has a broken tailcap. Tried opening it but my tweezers broke :(
Was able to open the pill but the board was soldered so cannot see the other side if the board.
For the tailcap measurement i get more or less 1.1 amp on both lights so both of them should
Be similar, tried another panasonic(from xiaomi powerbank) and still got similar reading. I tried using a thicker wire (don't know the gauge but about .3mm thick, reading imrpoved to 1.3 amp . Dont have a thicker wire now but will try it on weekend. I will also need a soldering iron to confirm the board really has 8x7135
Will post beamshot comparing it to my led lenser m3r
Do keep in mind that the retainer ring in the tailcap of a Convoy S2+ has a reverse thread. So if you try to loosen it by turning it in the anti-clockwise direction, you are actually tighten it even more.
0.3 mm wires are not thick 
use 1 mm or more and max 20 cm long ones
!http://i65.tinypic.com/j63986.jpg!
beamshot comparison against my 220 lumen led lenser m3r. Its funny that my led lenser feels dim
Compared to my convoy so i guess this light is really 1000 lumens?
Edit, can you help me.guys on the pic? Uploading pics in mobile just doesnt work
!{width:90%}http://i65.tinypic.com/j63986.jpg!:http://i65.tinypic.com/j63986.jpg
Can you recommend a tool for opening the tailcap?
The budget way, this is budgetlightforum after all, is to drive 2 nails through a piece of wood and bend them to the correct span of the retaining ring holes. That’s what I did and it works fine. Since I had nails and wood lying around the cost was essentially zero.
Here is Breinrules image.
That is actually a great idea! Thanks. With concrete nails, opening would be a breeze
Edit: thanks for the image fix.for the.guy above
Tweezers or a needle nose pliers.
I use an old circlip pliers Had to grind down the pins as they were too big.
Almost the same. I open retainer rings that are not super tight with an awl. If they are tight I use an awl plus a SS nail with a sharp point and I cross them so I can apply more force. When you apply too much force with the awl only, you push the ring in the thread and there it gets stuck on pure friction.
I don’t think it is. I know it ‘can’ make a difference. But it isn’t going to turn a 2.8amp reading into a 1amp reading. Even the worst of the worst DMM leads are going to be fine to see close to the 2.8amp reading.
I think there is some important information missing here.
You say you have two S2’s? Are they from the same vendor at the same time? If so, then it is reasonable to assume they are pretty identical (if you ordered the same thing twice).
If this is the case, it could allude to a spec or fault issue with this batch.
If however the lights came from different places, that would automatically rule that out of the equation.
To further this. I assume you are using the same batteries in both torches? Poor battery performance is often a cause of poor performance.
From your first post you mention capacity and amp rating of the driver. It’s important to note, that a batteries capacity (in mAh) has no direct bearing on how many amps it can delivery under discharge or load.
Amp draw and capacity are totally different things, just as engine power (bhp) and fuel tank capacity (gallons) are completely different things. And having a big fuel tank doesn’t equal that an engine is powerful.
I would highly recommend getting some good new batteries and trying those out first. Samsung 25R batteries are very good and very affordable:
I would advise grabbing a couple. And make sure you have a good charger.
In terms of measuring tailcap amp draw. Cheap DMM’s will often show some variance and stock leads have very high resistance, hence why you can see lower numbers when using them. But 2.8 to 1amp is too big a gap for this IMO. With a good battery, a stock DMM should see over 2amp. I actually run some fat 12 gauge wire on my DMM, as it does produce better more reliable results. It’s well worth looking into this for your readings too. But I think there is something else at play here.