A couple of weeks ago a member asked the question of which C8 was the strongest right out of the box and since I have several of the more popular C8’s I decided to try and get an answer. All of the lights are as purchased with no mods. I have the Xin TD V4, Lightmalls XM-L2 U2, Kaidomain C12 w/ XM-L2 U2, Lightmalls XM-l U3, Lightmalls XM-L U2, Trustfire XM-L T6 , Keygos KE-5 T6 & a Dongrui XP-E just for grins. I realize the last 2 are not actually C8’s but they are in the same form factor. We tested tail cap amps as well as lumens after 5 seconds and after 30 seconds. We used the 5 seconds instead of start up because a lot of these lights initial flash is way up there and unrealistic. We also did a candela test at 1 meter. These are not super throwers so we figure 1 meter is enough for an accurate throw reading. All lights were tested with unprotected Panasonic 3100 cells straight off of the charger. The I4 normally charges 4.19 to 4.20 volts. Here are the results:
In my opinion the Xin TD wins this contest hands down. It is the most mildly driven yet still ends up with the highest lumens and 2nd to the best throw.
thanks for the comparison.
so i see they enhanced the xintd. back then , they were known to be great cosmetically, and good in performance.
now its great in both.
i still think the lightmalls xml2 is best c8 for performance and value for price.
xintd is 1 1/2 times more expensive.
I’m kind of surprised that among the 3 Lightmalls ones that the U3 did the worst? The tailcap current was the highest of the 3, and yet it was the lowest in terms of both lumens and candelas. Weird!
You’re welcome. You guys did all the hard work… I just did some “grunt” work :).
That U3 thing still bothers me though, the reason being a situation that I had recently with a Shocker. In your case, the one you measured even under-performed the “lowest” one, the U2, and even with higher current. Doesn’t that imply that the “efficiency” of whatever emitter was in that light was less than the U2 one? So maybe it was like a T6 or something else older than a U2?
Sure seems like it. I bought the U3 from Lightmalls because my brother, Tom E and chriszhou all three seemed impressed with their U2’s from there but the U3 has never lived up to the U2. Even Driven like it is it performs poorly when compared to the 2 T6’s in the test. It doesn’t make sense.
That was me asking about the C8s and C12s. I ended up ordering a C12 w/XM-L2 U3 from Aliexpress. It isn’t here yet, and I don’t have any way to measure it, but I’ll report back when it comes in. Thanks for compiling all this info! I’m surprised all the C8s are so close in output. Were the differences in brightness very noticeable?
To the eye yes pretty similar. I thought about the Convoy after ordering the lightmalls XM-L2 and KD XM-L2 but I didn’t figure an XM-L U2 driven at only 2.8 amps could hang with these newer generation emitters but now I am not so sure.
I don’t have an IS, so I can’t measure lumens, but I do have a stock Convoy C8 from FT (“Convoy C8 Cree XM-L U2-1B 2-Group 3/5-Mode LED Flashlight”, SKU 1212403):
Lux: 21195 (21.195 Klux)
Tailcap: 2.78 amps
The above was with a freshly-charged EagleTac 2100
Note that the stock Convoy C8 comes with “Aluminum Textured/OP” reflector.
Thanks Comfy and ChiggerPepi, never realised the Nanj 7135 chip drivers were as efficient as they appear based on these figures, I’m assuming the other lights must have their own stock drivers. Of course other factors need to be taken into consideration like overdriving leds (KE-5 for eample),emitter bins or emitter performance, even so it seems reasonable to assume the 7135 drivers are just better.
Well, 'better' would be two cells and a buck driver, so that even when the cells are dead flat the input voltage is still above the LED's Vf, so it can be truly regulated from the start to the end. With a single cell and a CC driver you won't have a whole lot of runtime before the cell voltage falls below the LED's forward voltage necessary to pass the 2.8A/3A current and it behaves much like direct drive, but with multiple modes still available.
Agree with all of that, which is why I’m hoping a boost/buck driver becomes available at good amps on a single cell someday, in the mean time it looks like our 7135 nanj drivers are our best option for single cell applications.