Yes. Battery compression strength is extremely important, especially in regards to springs.
Low compression force by the battery in the spring can result in very high contact resistance, especially if the spring wire isn’t thick(0,8mm in this case) and if it’s made of a hard material, like steel, although a gold coating helps quite a bit since it’s soft, but the problem still remains.
That means two things to fix it in the Sofirn C8F for complete 18650 compatibility:
1. Making the springs longer and thicker to lower contact resistance significantly without changing the material.
2. Solder a small 2mm thick brass button on top of the springs. You will get maximum compression, therefore lowest contact resistance possible if you use it with an 18650. It would work with a 21700, granting you maximum performance possible by making the spring fully compressed, but you would probably sacrifice protected 21700 compatibility.
Just to be clear, I wasn’t questioning the max lumen output of this light. I was asking whether it can reach its max output in ramping mode, or if ramping mode is limited to some lower output. Some statements said ramping is limited to 1800 lumen then you have to press something to kick it up to max, while others said ramping goes all the way to 3500 lm.
Pretty sure the eye can’t compare 3500 lumens of light between different flashlights. You need a light box. The eye can easily misread hundreds of lumens, even a thousand. A slight difference in the beam profile or the tint of the output, the eye reads it differently.
The light box shows even small differences, whether or not the light box is 100% accurate it IS accurate at showing differences between lights or modifications. And that’s why we as individuals have light boxes, to show a gain or a loss when we are modding lights.
It was Moleyman69 that said his new 21700 light seemed weaker than his older 18650 version. I was wanting him to try double clicking to see if it improved.
I imagine we will get some good tests in the next week as more lights get delivered.
DB should have been refering to Moleyman69’s post about the new model C8F looking weaker than the older model. Moleyman69 does not have any measuring devices, just his eyes. I hope this clears up any confusion.
I do have measuring equipment - the light meter I mention in my first post #991 that produced the ceiling bounce comparison Turbo mode numbers that I listed - but it isn’t a very expensive one but it does seem to be consistent.
Also, it is the double-click Turbo modes that I am comparing.
Hope this helps to clear up any misunderstandings.
Okay.
A ceiling bounce test between lights that have the same beam pattern can be a good comparison.
So you have both versions of the C8F, but only an 18650 battery?
You’ve tried the new light at the top of the ramp and a dbl clk and it’s still weaker than the old light?
Keep in mind that part of the reason the new light is rated at a higher lumen is because of the more powerful 21700 cell. So in theory, both your lights should have about the same output.
What DB said about the longer battery tube on the new light not pushing the springs very hard against the battery ends might be a reason. If it pushes with very light contact it can create a lot of resistance.
Here’s something you can try. Take a short and thick piece of wire and bypass the tail cap. Run the wire between the negative battery end and the bare metal on the battery tube. At the same time push on the battery so it presses against the front spring firmly. If doing this gives you equal output to your older light then we know the light itself is okay.
Like with all new lights, you should make sure the driver and tail switch retaining rings are tight and haven’t loosened up in transport.
Did you successfully figure out how to switch from ramping to one of the other modes?
I’m still not sure how it’s done. Lol
You never explained what the lock ups where doing. Does it just stop responding or does it not register all of the clicks properly? Do you think your switch may not be making good contact or does it seem more like something in the software that is hanging up?
I just stuck an 18650 battery in to check performance in comparison to the 21700 and measured 420 lux for the 18650 against 460 lux for the 21700. The 18650 was a decent Klarus high current one.
So there is a bit of difference. Both batteries were fully charged.
With the light on and in ramping mode try clicking the side button 4 times on quick succession - the light should blink 2 times indicating that it has switched back in to Group 1.
Regarding lock ups I’m not sure if it is the side switch not responding or the light just “crashes” but for example when clicking between levels (not groups) I have had the light go Low > click > Medium > click > High > click > Low > click > Medium > click - nothing still in Medium > click - still nothing, still in Medium > click and hold - sometimes the light stays on other times it goes off. Then I pull the battery to start again.
Hopefully, the new cells might help shrugs - fingers crossed
