I had a bit of a problem with the retainer ring in the head of my FW3C. I finally removed it and the light works consistently xlnt.
My prob was a bit diff as I had tried to remove it with an inappropriate tool. When I tried it afterwards there was flicker after the initial flicker. I may have scored the retainer and caused a burr?? Anyway, removing it doesn’t seem to affect its operation.
Take the black ring off the tail and take out the switch (CAREFUL NOT TO LOSE THE NUB) and make sure all is aligned, I had a similar issue, the nub was sideways and not clicking the switch.
Check the brass ring in the head, in one of mine it was not installed properly and the board was moving around. I had to take it off and put it back on properly.
Make sure the driver board is centered. The contact ring should not be touching the brass ring and has to be aligned well enough to engage the inner tube.
Make sure to wipe off the unanodized parts of the inner ring, they need to make contact.
When you put the tail back on, do it carefully so everything stays aligned but leave the black ring off. I had to do that on one of mine, every time I tried to get it back on the switch stuff would get out of alignment, you don’t need the ring.
The unprotected cells that I was trying were Panasonic NCR18650A button tops. I tried several different ones and they all work fine in my various Zebralights.
I had salvaged some generic flat top 18650s from a bicycle light pack that had a bad cell. These work perfectly with my FW3C.
I like the tint and the UI.
I guess that I will now have to order some quality 18650 flat tops and an FW3T. And probably an FW3A while I am at it.
Like my Old Mentor who taught me about cars told me one time —- I was having trouble with a truck,when I would turn my lights on the gages would goes crazy then to zero—He told me check the body ground—Wow that was it — He said I’m not that smart —- It Happened To Me Before
There aren’t any standards in place for button top lengths, or lithium cells in general, so we do have to take care what battery we use. I think the maximum battery length is 66mm. Button top cells can be hit or miss.
There is no good reason to use high drain cells (unless your trying to measure the highest output possible). These lights get hot really quick by design. If your buying new cells, it might be better to go with high capacity versions.
I tried to use a Samsung 30Q on one of my FW3’s and it pushed the tail spring so hard it moved the switch assembly out of position. Had to re-set it and use a different battery. The Orbitronics 20 AMP work fine, they are shorter.
My button top Samsung 30Q worked fine. This is what I mean by there not being standards. Our cells probably had different height button tops added by different companies. Whoever added your button top probably used a slightly taller button then the company that installed my button top. :confounded: