Sofirn C8F 21700 Teardown and Review

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Barkuti
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LoL all of this current draw optimization treadmill is pretty crazy. I see the MOSFET used in the new 21700 C8F should provide some extra edge over the 18650 version, but it seems you do not get the expected results because of some “unaccounted” roadblock. At least on paper the newer PSMMN2R0-30YLE MOSFET is better than the AON6418 used in the 18650 C8F, but please note both MOSFETs are outside their optimal RDSon to VGS zone in the graphs, RDSon creeps much higher under ≈3.8V for both according to datasheets. Maybe going back to the AON6418 would “fix” this (= AON6418 “better” in practice)? Or using a MOSFET which actually works well with low VGS values. 

I do not really care about flashlight drag racing. To me the actual performance of my flashlights is the one I can always count/rely on nearly irrespective of battery SoC or temperature.

Preheating batteries to attain higher current draw LoL! 

 

Cheers Smile 

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JasonWW
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Barkuti wrote:

LoL all of this current draw optimization treadmill is pretty crazy. I see the MOSFET used in the new 21700 C8F should provide some extra edge over the 18650 version, but it seems you do not get the expected results because of some “unaccounted” roadblock. At least on paper the newer PSMMN2R0-30YLE MOSFET is better than the 1.pdf”>AON6418 used in the 18650 C8F, but please note both MOSFETs are outside their optimal RDSon to VGS zone in the graphs, RDSon creeps much higher under ≈3.8V for both according to datasheets. Maybe going back to the AON6418 would “fix” this (= AON6418 “better” in practice)? Or using a MOSFET which actually works well with low VGS values. 


I do not really care about flashlight drag racing. To me the actual performance of my flashlights is the one I can always count/rely on nearly irrespective of battery SoC or temperature.


Preheating batteries to attain higher current draw LoL! 


Cheers Smile 


I wish I understood more about the mosfet specifications, but I barely understand how they work. Lol

I’m not sure why you talk about preheating a battery to get better performance. I don’t think that was mentioned in this thread.

I agree that trying to get maximum amperage is not very practical. It just heats up the head and runs down the battery quicker.

I switched over to using the Sofirn SP33 v2. It’s got a nice regulated output. It doesn’t build up heat very fast and the battery lasts a longer time.

Barkuti
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JasonWW wrote:

Lol I'm not sure why you talk about preheating a battery to get better performance. I don't think that was mentioned in this thread.

Yes it's been mentioned by… yourself! 

JasonWW wrote:

He may know a few other tricks to boost output as well. Like using warm batteries fresh off the charger. I've heard warming up the batteries gives them some extra oomph. He might replace the lenses with UCP which have lower losses, etc... Dale just gets all the highest output. I can't compete with him. He's the king! Lol

 

Cheers Party 

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JasonWW
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Barkuti wrote:

JasonWW wrote:

Lol I’m not sure why you talk about preheating a battery to get better performance. I don’t think that was mentioned in this thread.



Yes it’s been mentioned by… yourself! 


JasonWW wrote:

He may know a few other tricks to boost output as well. Like using warm batteries fresh off the charger. I’ve heard warming up the batteries gives them some extra oomph. He might replace the lenses with UCP which have lower losses, etc… Dale just gets all the highest output. I can’t compete with him. He’s the king! Lol

 


Cheers Party 


Oh yeah! I forgot. Lol
d_t_a
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I recently ordered another Sofirn C8F-21700, and noticed that the tailspring is now not factory-bypassed (left), but instead uses a double-spring (right).

I think they now have the same tailspring as the Sofirn C8G (which also uses the double-spring).  (I tested that the C8G and C8F-21700 are interchangeable)

 

 

 

Any idea if which one is better? Which can pass higher current?

 

I notice that Sofirn's factory bypass wires tends to get detached when using high-drain batteries (at least that's what happened on the Sofirn C8A and Sofirn C8F-18650 when I was testing Turbo mode for a bit longer time, and notice the factory spring-bypass wire on both sides got detached probably due to heat -- and I'm not good at soldering small parts)..

Barkuti
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Properly done spring bypasses require wire coiling. Without it, chances for the wire to break are substantially higher. So either do a custom spring bypass, or use the double spring is my advice.

 

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ZozzV6
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As Barkuti said. Properly done wire bypass gives higher current but double springs far more reliable. Even a properly done wire bypass can break over years.

Barkuti
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User BlueSwordM can provide some nice high current springs. Check this thread: http://budgetlightforum.com/node/67401.

 

Party 

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contactcr
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I hate putting springs on boards like this. They always seem to fall in that green solder mask area. Not even sure what the purpose of making it like that is

Mantser
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Hello everyone, where to buy a reflector “orange peel” for this flashlight? I really need this reflector! Thank you.

JasonWW
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Mantser wrote:
Hello everyone, where to buy a reflector “orange peel” for this flashlight? I really need this reflector! Thank you.

I’m not aware such a thing exists.

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