Just got my 18650 batteries yesterday and my Solarforce xpg drop in only pulled 1.44 amps off either battery. Guess mine will be safe and its enough output for me, for now.
Tried to reflow the emitter back? Perhaps a driver switch would be in order too.
Hobbyfotograaf, w as your Uniquefire multi-mode driver, or pure direct drive? Either way, I wonder how much those multi-mode drivers bleed off when in "high" mode.
I have read of XP-G's solder becoming liquid and the emitters then falling out. Yeah, I would call that an overheat situation ;) .
It was the 5-mode Uniquefire L2 http://www.dealextreme.com/p/uniquefire-l2-cree-xpg-r5-5-mode-320-lumen-led-flashlight-black-1-18650-33549
The driver is not regulated:
4,2V high -> 1,9A / 4,15V high -> 1,6A / 3,7V high -> 0,96A
With that driver i did not even try to replace the led, because it won't last very long. The led was fried after only 1km (the temperature was about 2°C)...
Oh, okay... you had it on high, while you were riding a bike (leaving it on for an extended time). I think that explains it. I don't run ANY of my multi-mode lights on high for more than 2-3 minutes at a time. Maybe why I haven't had a problem.
I know some people say the air from the bike should cool the flashlight, but that's only if the heat can get to the body quickly enough... which obviously wasn't true in your case.
In my mind, the difference between a so-called "duty" light (meaning: "expensive"), and a well-driven "budget" light consists of several things, but most importantly the ability to run on High indefinitely, without damage to any components. Case in point: 4sevens Maelstrom XM-L. For around $150. Has active thermal sensing/management to prevent overheating, so you can run it on High however long you want. After some experience, I think the 2nd most important difference between "budget" and so-called "professional" lights would (or should) be the switch, surprisingly enough (ability to handle high current and keep working reliably). The LED's themselves are down on the list; Cree pretty much rules the roost, and the main difference, if any, is tint and flux bin. I think the 3rd would be reflector... but there are some pretty good reflectors out there in budget lights nowadays. My Ultrafire XM-L smooth 3-mode drop-in reflector has no rings, for example. Even Fenix's IIRC commonly had rings a few years ago. As much of an issue as people make about quality of threading, and yes it is probably the best indicator of how much expertise went into machining the flashlight, so far that hasn't made much of a substantive or tangible difference to me in actual use yet (when assembled), nor has finish, because aluminum isn't going to rust away if the coating chips off. Doesn't mean those things aren't important, just talking about what is going to cause your light to completely fail (while in use), like yours did.
There are guides all over the place, here's one - http://www.instructables.com/id/Toaster-Oven-Reflow-Soldering-BGA/
Guess this is the reason I keep bragging about the N-light b2s stainless steel light
2.05 amps on high @4.10volts
1.40 amps on med
.22 on low
on a AA it's a nice light ..with a 14500 , Everyone says ...damn !!! 
You know what brjones, that is an incredibly valid point. We can brag about our cheap uberlights being better than x name brand all day long but what about just using them like a tool, with regard to the job at hand and not the tool itself? When I have a bang-around task to accomplish I use my 4Sevens Quark AA2 because it already has beat-to-hell annodizing. Yet, it turns on and runs on high no matter what until the batteries die with no issues.
Foy
+2, if we wanted EDC reliability because our job or life depended on it, we should be buying Surefires or a $200 HDS light.
Then again, I have probably spent $200 on a bunch of cheap lights and parts in the last month. Wonder if that is better than having just one really great light????????????????
[quote=trooplewis]
+2, if we wanted EDC reliability because our job or life depended on it, we should be buying Surefires or a $200 HDS light.
[/quote]
I disagree. A fancy name and high cost does not guarentee reliability. Heck, I'd put Romisen and Solarforce up against those two. Only thing needed is to check solder joints and O-rings (two most probable failure points).
I would take an HDS rotary over 4 Solarforce L2's with Ultrafire dropins anyday. The programability, high efficiency, and Rotary control interface, along with rock solid build and plenty of light, would be far more important to me than massive light, if used for a serious job.
The fact that you have to check solder joints and driver issues, and bad switches, is what deters me from using a budget light when I really need one.
But have fun building and designing a well built, indestructible host for that-bonus points if its programmable between 0.07 and 200 lumens, with 3 modes activated by 1/2/3 clicks, and a rotary interface to select any level.
For me that is a fact. I would, and have, do that on any light I own and want to trust. Call me a cynic, but I've worked as and around enough engineers long enough that there's no great mystery to me surrounding good design. If you feel the need to spend $200 to trust a light, so be it. As for me, I won't trust a device until I've had a chance to go through it. Keep in mind though....at the end of the day, it's just a flashlight...
Last point: Most folks here have had great success with inexpensive lights...may want to remember where you are.
[quote= OldBobk]
The only way to be completely certain of your lights' reliability is to build them yourself.
[/quote]
Amen Brother. You understand why I do what I do. (also, because it's fun as hell 
).
I dont mind paying money for quality. I dont like paying a huge amount of mark up for just a name. Some budget lights are junk. Some are are what you expect, alright for the price. Some are true bargains with very good quality. Thats why we are all here, to weed out the junk. If you buy an expensive light it better work, it has a warranty if it doesn't. Thats what you are paying for sometimes I think, (notice I said sometimes, not always). For me, I already spend enough on "insurance" so I will enjoy the savings with my "budget" lights. If I paid 200 bucks for a light I would be scared to use it, honestly!
I think you just summed up BLF perfectly for me. :)
I just got a low voltage (0.4-4.2V) 3 mode XP-G drop-in from Solarforce-sales. It seems OK in low current/low voltage situations (AA or AAA NiMH), but it gets surprisingly hot with a single 16340 and overheats (starts blinking and smelling like something is burning) in less than a minute with a single 18650.
I've already emailed them about this. I don't see how they can advertise run times with an 18650 for this drop-in if it will self-destruct within the span of single 18650 charge.
Thanks, Bob. This is useful information. Aside from this drop-in, I've been very happy with the quality of everything I've gotten from solarforce-sales. (In the same order, I got an L2p and XM-L drop-in, and some other parts that are are great.) From what I've heard so far, their customer service has been exemplary, so hopefully there will be a good resolution of this.
Thanks again.
I run mine only on 18650 now and on high alot, just gets warm too.
Match, I sort of agree and sort of disagree when it comes to taking budget lights apart and checking things.
I like the analogy of buying a cheap car (lets say, a Hyundai) versus an expensive car (like a BMW, which I sell).
When I get the brand new Hyundai home I still expect it to start without me going through it to fix stuff. It may not perform like a bimmer, but I still expect it to perform the basic car functions I need with reliability. So I try to avoid the junk lights, and stick with the mid-price budget lights. I don't want to build them, I just want to use them. Ok, I'm good with assembling them, but I don't own a soldering iron so don't even go there with my new light!