Sofirn C8A lumens over 3 min timer (issue)

C8A test
C8T test

The C8A step down of 3 minutes is too long. At the 1 min mark the lumens start decreasing and at 3 min it’s at 780. Shortly after it does a hard step down to 580.

This shows it can’t handle the heat?. Sofirn needs to redesign the driver and please add more brightness levels. A step down from 2000 lumens to 580 is terrible without anything in between. The C8T drops from 1250 lumens to just 380.

I’m always having to swap the driver on the C8A and sometimes on the C8T due to the bug below.

The driver also has a bug where the low voltage warning starts flashing randomly. Has happened on approx 6 out of 20 (I sell them). Usually on a Samsung INR18650-30Q or higher current cell.

I have that driver in a Convoy C8. It too flashes randomly sometimes. Only cure is to change it?

Lumen measurement without current and head temperature measured does not show it overheats
Battery also depleets
Also decreasing current or resistance increasing hot springs do voltage drop

If it would you could simply tell that the LED went blue

If you sell them why not order from them just hosts and install a better driver?

They have a spring bypass so wouldn’t that eliminate the resistance in springs?

The Sofirn C8T only loses 130 lumens over 3 min. The C8A loses over 1200. i know about voltage sag but I’m using a Samsung 30Q

From 2000 lumens to 780 is showing something wrong? It shouldn’t be dropping that low

I still have a few in stock that I purchased complete. I’ll probably switch to the Convoy C8 with the SST40

The C8A & C8T use the exact same driver with a hard step down at 3 min. It seems odd for the C8A to lose so much output

I’ll run another test tomorrow

That’s because the VF of the XP-L2 of the C8A is much lower than the XP-L HI.

That means the C8A draws a lot more power to produce a lot more lumens, which makes the stepdown much quicker.

I’ll test again tomorrow and once it reaches 3 min I’ll switch the light quickly off and on, if the lumens go straight back up and stay there for the next min then something isn’t working right? If it’s a voltage sag issue if shouldn’t increase in lumens for more than a few seconds

I also have both the C8A and C8T.

The C8A does get very very hot with the default 3 minute timer-based stepdown.
Maybe “overheating” is not the right term here … “overheat” would imply some internal parts starting to get damaged or show signs like the LED getting blue.

On my test of the C8A, the factory bypassed wire always gets broken/desoldered to the heat or high current? I’m not good at soldering small stuff so I have left it in the “broken spring-bypass wire). The lux (I got the HS1010A lux meter but don’t have any light-measuring tube setup) I get with the broken bypass wire is lower than when it was still bypassed (did you check if the C8A bypass wire on both sides got disconnected too from the high current/heat?)

New Test

Ran a new test and at 3 min I switched the light off and on quickly and it jumped to 1900 lumens and slowly decreased.

This rules out voltage sag on the battery. The springs weren’t hot either. As mentioned by others it’s not overheating, if it was it wouldn’t jump up to 1900 lumens.

This is the same driver as the C8T and that doesn’t behave like the C8A.

Anyone have any ideas as to why the lumens drop off like that?. I thought maybe the driver was adjusting to the heat but they don’t have this feature

I also have the Sofirn C8A and C8T (bought both from Sofirn store on AliExpress). Have had both about 6 months and haven’t used either much at all. Casual stroll outside for a bit to piss off the neighbors and that’s about it. My C8T has started acting up. It’s like it can’t make up it’s mind which mode it wants to be in. Just starts random blinking and mode switching and no amount of clicks does anything. Switched batteries up the kazoo and that does nothing. It suddenly has a mind of it’s own like it turned into a zombie light. I just turn flashlights on and off, I can’t mod or fix them (I’m a dumb ass, when they break I’m fucked). Just ordered another one cause they are so cheap and this light gave my eye brows a work out before it started screwing up. I hope Sofirn gives me more than 6 months on the next one. I sure don’t want to get the impression that Sofirn is a disposable flashlight, use it a few times and throw it away. Hope I get a good one next time.

First thing you need to check is the retaining rings are screwed on tight on the driver and tail cap. This can cause the behavior you’re experiencing

Dude. I can’t even put into words how stupid and sheepish I feel right now. Checked the retaining ring on tail cap and turned it a bit. Light is fixed! Jeez. I think I’m just going to go put my head in the oven and turn the gas on cause I just made myself look like a roasted weinie. lol. Funtastic, you were like Motel 6, you turned the light on for me.

Hi! I am relatively new here at the forum and bought a C8A based on your reviews (Bought the light from Shopee Philippines).

I have a question for you guys, does the Sofirn C8A have heat issues? I have read from some of the reviews that the light should throttle down if it reaches a certain heat range.

I had mine for 3 days and decided to use turbo mode until the light goes off by itself ( used freshly charged Sofirn battery that came with the kit) , I woke up the next morning to find the light is no longer working. (Tried newly charged batteries, but it still won’t turn on).

Upon closer inspection, I found some metal flakes floating inside the reflector. I Then turned my attention to the led emitter and found it separated from the copper board and somehow lodged itself to the back of the reflector housing.

Aside from the led that got dislodged, I also found the tail cap spring was totally deformed and a positive wire that is soldered to the copper board broken from its solder.

My initial thoughts where heat damage. Did any body have the same issues? As of now I am still waiting for the replacement (Just added extra and got the C8F instead).

Ummm, you flicked on the light, on turbo, left it unattended, overnight?? :person_facepalming:

That’s like buying a car, gassing it up, starting it, bricking the accelerator, and leaving it overnight.

Not Recommended.

Wow, yeah, that might not have been the wisest idea. Damn dangerous for sure. Lots of possible bad endings.

The C8A is suppose to have a 3 minute timer as you may have already read. A few reasons that could happen but, it’s too late now to tell. Chalk it up as a relatively inexpensive learning experience and move on. I personally wouldn’t try that trick twice.

I would just order a new driver and MCPCB with emitter and call it a working light again.

Left it to illuminate a stop sign for manning a checkpoint on a busy highway.

Anyways, I told my buddies to leave it on high because I was sure it would throttle down as it reaches a certain temperature.

I Was told by barry at Sofirn that parts would be delayed due to the Covid outbreak. Good thing I got three of these lights. Anyways thanks for the insight.

Sofirn C8A with a fully-charged high-drain battery will produce a lot of light (possibly more than the stated “1750” lumens, and closer to 2000 lumens).
It will also get very hot. I’m not very sure if the C8A has a temperature stepdown, or probably just a timer stepdown (2 or 3 minutes).

I wouldn’t recommend to leave the C8A on High mode for extended period of time since it does get quite hot. (basically similar to the Sofirn SP32A v1).

I’d like to relate what I remember when I tested the C8F (original 18650 version instead of the later 21700 version)
Regarding the C8F, I tested leaving the Sofirn C8F-18650 version on Turbo mode but monitored it when I first tested it. I recall the light stepped down, but I double-clicked again to go to Turbo mode. I remember the light automatically shut off the second time (I think around 5-6 minutes from when I first initially turned on to Turbo mode). The flashlight was extremely hot to touch. When I tried to turn it on, the light didn’t turn on (from what I remember). Anyway, I left the flashlight to cool down first (it was Off already). The next morning, the flashlight worked normally and there didn’t seem to have any issues, other than the spring-bypass wires on both head and tailspring are now broken, which also resulted in a slightly dimmer Turbo mode.

I haven’t tried subjecting the C8F-21700 to the same “leave it on Turbo” mode yet, but the flashlight does get hot, so I would exercise care when setting these flashlights to Turbo mode and try not to leave them unattended on Turbo…