Sofirn C8A lumens over 3 min timer (issue)

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Funtastic
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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.

Texas Ace Lumen Tube calibrated with maukka lights

Edited by: Funtastic on 06/18/2019 - 02:07
pennzy
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I have that driver in a Convoy C8. It too flashes randomly sometimes. Only cure is to change it?

Lexel
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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?

Funtastic
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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

Texas Ace Lumen Tube calibrated with maukka lights

BlueSwordM
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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.

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

Funtastic
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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

Texas Ace Lumen Tube calibrated with maukka lights

d_t_a
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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?)

Funtastic
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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

Texas Ace Lumen Tube calibrated with maukka lights

Mike89
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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.

Funtastic
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Mike89 wrote:
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

Texas Ace Lumen Tube calibrated with maukka lights

Mike89
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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.