I've noticed several posts (one in particular) talking about some budget XM-L drop ins failing in a rather short period of time.
I've got several on order, and from different web sites; one from eBay (Flashlight Family), one from manafont, and I can't remember where the other is coming from.
I'd like to get a general poll if you have purchased an XM-L drop-in
1) How long have you had it
2) Has it died on you? If yes, any idea why?
3) Where did you get it from?
4) If it died, did it die of natural caused or did you overclock it?
Just trying to figure out with the growing popularity of the XM-L, are there specific applications we need to avoid or do all have a high chance of being short-lived? If there is another thread that deals with this I have not been able to find it, so feel free to direct me there.
Most problems are caused by overheating because the heat of the led does not get out of the flashlight. In most drop-in flashlights there is no thermal contact between the drop-in and the flashlight body. With a XM-L at full-power, it is about 10W that needs to get away from the led. If the heatsinking is not perfect, the led will overheat.
I have a 5-mode XM-L drop-in from DX, but that is not driven to the maximum power.
4) If it died, did it die of natural caused or did you overclock it?
answers:
1) up to 2 good months (snatched the first available at KD)
2) No
3) Manafont (3 mode H-M-L) 2x, Manafont <- the best ones, KD 1x XM-L flashlight (P60) and two lone XM-L's that were a bargain at 12,90usd each for a day
4) NA
I do the foil trick and do not leave them on on a desk and walk away so it does cook itself. :)
3 XM-L drop-ins. 1 is KD 5-mode, 2 are Manafont Ultrafire 3-mode (High-Medium-Low version).
No failures.
Manafont/Ultrafire are 'thermally potted' with a black disc of some type of substance around the LED emitter. KD driven a little less hard, but still well-driven, but no thermal potting. I added that myself. Might do a pictorial on that if there's demand for it. Not sure how much that really helped. The flashlight body does seem to heat up 'a little' faster now (I also use the aluminum foil strips).
No obvious dimming on any at this point. I don't run for long times on high (or even other levels). Besides, running a long time on high with these is kind of an... oxymoron.
Something else to consider is the voltage of the battery dips as it is run hard on high, which limits the current output taken by the LED. Also, the LED's Vf rises as it heats up, which also limits the current. Although not by design, and not foolproof, they do both work to also reduce what otherwise would be more overheating. You'll notice that after a few minutes on high, switching to Medium is really not that much dimmer. So, for both reasons, best to switch out of High after a few (I'd say 2-3) minutes. Another thing to consider is the XM-L seems to, by design, handle heat quite well. I believe Cree targets these for municipal lighting.
It's a good time to be into LED's. I remember my first white LED flashlight, the Eternalight... Come to think of it, I'm going to start a thread on it.
2 dropins, 1 Manafont and one KD. Both have given no trouble. Bought both of them in January and both are at the back door for dog-spotting duties at night (She likes to empty herself at 4am) so they see a lot of use on full power.
Hehe, the single-mode solarforce XM-L T6 dropin in my surefire 6P is the reason why I did not use my extra solarforce clickie cap on that particular light. No matter what I stuff inside the body, be it primary cells or two 16350s, they get friggin' HAWT after a few minutes. Mighty brighty, but calling this emitter with a single-mode driver "thermally handicapped" is quite an understatement, despite two feet of aluminum foil tightly wrapped and crammed in there (press fit). Not a show light though, those short bursts are perfect for spotting feral hogs in our vineyards at night. Count 'em, then order the tenant of the hunt to take appropriate measures of population control. Hmmm, wild boar ragout in late burgundy wine... :love:
Three more XM-L dropins are on their way from Manafont (thanks Old4570 for pointing out, recently!), to modernize some of my older 3AAA lights (More on that when I finally get my lathe working again). I guess this will be great. Test-fitting the solarforce pill (minus reflector and no heatsinking at all) to a 3xAAA battery-pack cranked out decent lumens and produced only very little heat at all. Fascinating.
I suspect you could probably kill one quite easily by putting it in a loose fitting body, using a good high capacity cell and then leaving it on full power untill it cooks it's self.
I have four XM-L drop-ins; two single modes from Solarforce and two Ultra Fire 3-modes from Manafont.
No failures yet but I take precautions because I know the limitations of the P60. First, I alternately wrap aluminum foil and screw down the head repeatedly until I can just barely screw the head on all the way. Then, I never run my single mode XM-L lights long enough at a time for excessive heat to develop. Actually, I've found the L2P can run for quite a while on high before getting too hot. One must accept the heat transfer capabilities of the P60 host.
One KD 5 mode and one Manafont 3 mode, both press fit into L2Ps lined with aluminum can strips. Both run fine on high for up to 25 minutes outside. I don't use them at all indoors.
Only have one XML. It's a 5 mode from the 12$ KD deal. It's on a Solarforce L2P SE, and wraped with aluminium foil. It is used mainly outdoors and on high.
Still running since February. Probably has 5-10hours use.