Agreed. It sounds like the switch wires are out of position and getting pinched. Might be that one of the wires is under the edge of the board and is getting squeeze when you insert the battery.
This could account for all of the problems you are experiencing:
switch wire raising up one edge of the board and getting pinched could account for the odd behavior of the light acting as if the button is being held down when the battery tube is screwed in all the way.
also because the wire is probably only lifting up one edge of the driver, the driver is unable to get firm contact with the battery tube. The result is a bad ground connection that could be causing the low voltage stepdown you are experiencing.
because the problem is on the other side of the driver, no amount of smoothing out the nick in the battery tube will make any difference.
Solution:
unscrew the bezel and remove the optic. Desolder the driver wires. Then following the pictures in in Toykeeper’s first post in this thread use a spudger or other device to push the driver out.
once the driver is removed check the switch wires for creases. If you see any kinks, creases or flattened areas that switch wire is probably compromised. I suggest desoldering and replacing it. This could be difficult as the switch is hard to access (you will probably need to remove the switch retaining ring and rubber boot.
once all wires are checked and, if necessary, replaced, reassemble.
If you’re not comfortable with your soldering skills, your best best bet is to return the light to where you bought it and have the seller fix it.
ledalex, it sounds like you probably have a switch wire crushed between the outer edge of the driver and the shelf it’s supposed to rest on. This would make it think the button is pressed when the battery tube is tightened, and could also explain why one side of the driver is getting so much more wear than the other.
Fixing that would require soldering, and possibly also replacing the wire… which isn’t easy to replace due to the way the pill is constructed. I’m guessing the wire should still work without being replaced though; it probably just needs to be re-positioned.
So it’s back to stepping down after 5 seconds (even with a fully charged 30q)
And there’s no way this light is anywhere close 4300 lumens. Even on high during the 5 seconds before stepdown, bouncing this off the ceiling seems to produce maybe 1/4th (probably less) the amount of light as a convoy l6.
Really disappointed. Should have known this light was too good to be true.
You almost certainly have a bad driver switch wire and a bad ground connection. The performance you are seeing from your light probably doesn’t come anywhere close to matching that of a fully functioning D4.
If your D4 was working properly it should be VERY bright. My XPL HI D4 is my second brightest light… it’s MUCH brighter than all my single-emitter lights (even my XHP70 light) and all my triples. The only brighter light I own is my 6300 lumen Noctigon M43.
Checking the stats on the Convoy L6: I see that it is a 3800 lumen XHP70 light. The difference between 3800 lumen and 4300 lumen is quite small. In a ceiling bounce test it may be difficult to tell which one is brighter. The L6 is a much bigger light, has much more heatsinking and runs on 2x26650 cells. I expect it should start slightly dimmer than a fully functioning D4, but the D4’s output should decline fairly rapidly while the L6 maintains its brightness much longer.
Also are you doing the ceiling bounce test correctly? I do ceiling bounce comparisons the following way:
hold both lights over your head pointing towards the ceiling with one light in each hand.
tilt your head down and look at an object on the floor.
turn one light on for 5 seconds or so. Then turn it off and turn the other hand. While you are doing that continue to watch the object on the floor and note which light makes the object look brighter or if you can’t tell.
During a ceiling bounce test the hotspots on the ceiling should NOT be in your field of view. Lumens is a measure of the total amount of light produced by a light. A light with a very tight and intense hotspot might produce fewer lumens than a light with a much dimmer, but wider, hotspot. If you’re looking at the hotspots you’re comparing lux (throw), not lumens.
Yes. It looks like the XPL HI version actually runs the coolest. I briefly tried a very unscientific test where I held my XPL HI D4 in my right hand and my XPG2 one in my left. Turned them both on to turbo. The XPG2 seemed to get too hot to hold faster.
Yeah I’m definitely doing the bounce test correctly. The light output from the bounced D4 is about 1/4th as bright as when I bounce just the L6. It’s hard not to notice the difference.
I contacted mountain but have not heard back. Hopefully they’ll be able to get me a new one delivered by next week as I bought this light hoping to use it on my vacation which I’ll be leaving for this month.
XP-L HI should have higher amps than XP-G2, no? It has a lower Vf curve so it should max out at higher amps. Its efficiency doesn’t exceed XP-G2 until like 2900 lumens, so there shouldn’t be such a big gap between them on turbo.
In the numbers above, 219c and XP-L HI are both listed at 3.42 V, but one shows 4.92 A while the other has 3.10 A. That can’t be right. XP-L HI should have both higher volts and higher amps on turbo, like maybe 3.6V and 4.0A, at a very rough guess.
Regardless, I reduced the number of peppers for XP-L HI.
It’d be useful to have a way to actually graph the temperature for each, but I don’t have a thermocouple for my DMM.
Just wanted to add that it’s also sometimes varying in output and sometimes just strobing at the lowest output and sometimes flickering when it’s on. I think it’s definitely nowhere near the max output because it barely gets warm.
I’m going to see what Mountain says before I investigate trying to repair it myself (I haven’t soldered in a long time though and I think my soldering iron is in a different state so I’ll probably have to get another one. although I do want to start modding things so maybe this will be a good excuse to get another iron). Maybe I can find another flashlight enthusiast in Los Angeles who would be willing to help me out.
I’m hoping Mountain will be able to take care of me but I’ve never ordered anything else from them (everything I want is always out of stock) so I don’t know what their customer service is like.
your light is definitely defective. On turbo with the temp sensor off the head of this light should get too hot to touch in probably around 20 seconds. If yours is getting barely warm it’s pulling far less amps than it should.
I absolutely agree that that doesn’t seem correct. My best guess is that the optic is a lot more inefficient with the XP-L HI as compared to the other two LEDs and I’m not accounting for that. Either that, or the 4300 lm is underrated.
If you have the V2 it looks like you can just ramp to ~500 lumens and use Fast Click to turn it on and off thereafter, memory will retain your level.
Perhaps a level lock or single mode use is a feature that could be built in to future versions if there is a demand.
The reasons for this have been discussed in this thread in a fair amount of detail. The 219C is generally pretty similar in efficiency to the XP-G2, but in a direct-drive light, the emitter that draws the most current tends to be least efficient because all LEDs lose efficiency at high power. Using medium modes doesn’t help with this because they’re produced using PWM; the LED is rapidly turned on and off, and the percentage of time it’s on determines the brightness, so it’s always operating at the worst efficiency the battery has power for.
Forward voltage determines how much power the emitters can pull from a given battery. Lower voltage = more power. The 219C has much lower forward voltage than the XP-G2 and a fair bit lower than the XP-L HI.
On low modes, the D4 uses a linear regulator. This runs the emitters at the same current regardless of voltage, where the 219C should actually be more efficient in terms of lumens per watt. The linear regulator turns any voltage the LED doesn’t need into heat so the whole system is still a little less efficient with the 219C.
With a current-controlled buck, boost or buck/boost driver, the 219C has much better efficiency than in a linear or direct-drive configuration. Compare the two emitters in a Fenix TK25 - XP-G2 left, 219C right:
