LG 365nm UV led tested (LEUVA33W70RL00, from Simon)

No, it is the cleaned one :frowning: , probably it will not influence performance but the silicon has some pits here and there.

Probably not the correct place to ask this question, but was wondering…

Convoy sells the Convoy S2 with LG UV LED. I wonder if that Convoy S2 uses the older LG or the newer LG UV365 LED?

Thanks again Djozz for the testing!! Djozz-mW...that's funny :D

I can Pay Scientist

Thanks for the test, djozz.

Looking at if from the other direction it means the radiant output at 3.7 V is not 1070 djozz-mW (at 0.8 A) but 2100 djozz-mW (at 2 A).
That is a huge difference.

This is probably hijacking your thread a little, but the knowledgeable folks who I have conversed with over the centuries are here, and the topic is UV LEDs.
Despite all the recent claims of 4 watt, 5 watt, overdriven, turbo Convoys (7135 drivers), I believe there ain’t no such animal. The engineers in our fluorescent mineral group have watched the ridiculous power claims climb over the past three years with amazement At the power levels folks are claiming today these little lights should literally be burning your hands. They aren’t - this blog post explains why, all comments welcome: Convoy false power claims

dude the 7135 is a linear regulator

Sure is, but I don’t understand your point

I'm not sure what you're getting at. You may be correct regarding the high Vf of the UV LEDs preventing high output on the UV Convoy, but the Convoy hosts are capable of dissipating over 7W of heat. I've personally run a Convoy on a fresh cell for hours at approximately 2A. Not much sag on that cell, but I'll be generous and assumed 2A * 3.5V for the power dissipation. For short periods, they handle significantly higher power well - not just the stock 2.8A that the white Convoy's come equipped for, but so-called hot-rodded Convoys can pull currents in the high teens.

Even your own chart shows the Convoy doing 3 Watts at 3.9V, which could be sustained for a while before the battery got that low - definitely more than just a few minutes.

700mA is very little current, it won’t burn your hands (but it could damage the Nichia LED if the heat transfer to the star and pill is not good enough as that LED is quite small, the LG LED can handle more current but has more visible light). Even 1400mA shouldn’t get too hot. 2100mA (6x7135) and 2800mA (8x7135) can indeed get quite hot to painful levels if left unattended. There was a temperature test of the 8x7135 driver: How hot does an S2+ get at 2.75A? Comparing an anodised Convoy S2+ with a fluorescent yellow powdercoated Convoy S2+

I guess that a 4.35V cell like the LG ICR18650E1 would be better for extended usage of the Nichia version.

Edit: you are making your claims based on a ‘typical’ 2200mAh cell. Nowadays 2200mAh would be either an obsolete or cheap cell, or a cell optimized for very high current for power tools or vaping (20A-30A) rather than capacity, not a typical 18650 cell. A modern cell 4.2V cell like the NCR18650GA can keep the voltage much better. In fact a 4.35v cell isn’t a large improvement over the 18650GA. From HKJ’s battery comparator :

It means a 7135 based driver will maintain a constant current until it can’t sustain it anymore. So a 1x7135 (standard bin 350mA) driver will maintain 350mA , nothing more, nothing less until 3.6V ish, and shortly after that turn off. It will not dim from 4.2 down to 3.6 unless you apply PWM.

Not too worried about heat, just driving voltage. But that said, UV LEDs are much more sensitive to heat - just look at any graph, derating starts at 40c on most of them. Of course hobbyists can do all kinds of neat things, drive them harder, etc. But production flashlights to the masses, probably a bad practice.
As far as voltage goes, drop below 4 volts and the current to the average UV LED drops drastically. 3.7v (rating for lithiums) and it really sucks.

Don’t think so. The driver just goes into direct drive mode. The LED will light (in the case of an LG or Nichia LED) as long as the battery voltage is high enough >3.0V~, but will progressively become very dim as the voltage drops from 3.9v to 3.0v (or so). PWM another story, I’m talking about single mode drivers, no smarts. edit - keep in mind that UV LEDs expect ~4.0v

and I’ll repeat, 7135’s are not direct drive

Maybe a little better but according to the graphs it still drops below 4.0v pretty quick it seems. But in our market we have a bunch of people who have no clue about batteries and buy them off Ebay, your local vape shop, Amazon, etc. No idea what they’re gonna get (except the cheapest). In fact, folks selling Convoys to the mineral market on Ebay and at shows are including really junk batteries.
I’ll dig into the one you linked to see if we can get a little better run time - thx for the link. But sadly, won’t help the general population.

…and I’ll link this: AMC 8*7135 3A CC driver is in fact direct drive
“AMC 8*7135 3A CC driver is in fact direct drive” (but I’m always eager to learn)

Linear driver are never in direct drive.

As long as the battery voltage is high enough, constant current will be sustained.

The problem is that many lights don’t have an optimized current path. It’s not much of a problem with current low VF LEDs…

But it is a problem with high VF LEDs.

Voltage drop over the springs, over the switch, and the wires can be solved.

Using copper alloy springs, thicker 20AWG wires and a thick mechanical/FET switch, we can get max regulated runtime on UV LEDs.

The perfect driver for UV LEDs would be a linear/boost driver.

Right so since UV emitters require 3.8V it’ll sag once it hits that point, but it’s NOT what you make it out to be, certainly not what’s in your article. With a 2*7135, you never get 4.2v, it’s 700ma @ 3.8V. To compensate, you can just use more 7135’s.

I guess that’s my point exactly. UV LEDs require a boost driver to run off 3.7v and lower, a buck/linear at 4.2v. But problem solved if you go to a two battery solution and driver, but not feasible for a Convoy as marketed. (Please let’s not get into CR123s - whole ’nother set of problems).

UV emitters range from 3.7v to 4.2v. Out of the hundreds of LG parts I’ve used, the ones I have tested are all 4.0v. The Nichias I have tested are also 4v. I wish I could get the lower voltage bins, but not easy, and probably pricey? 7135s will drive the LED at its Vf as long as you supply a tad more at the input.