New Folomov 18650s

was the cell overcharged ?

The most interesting thing about this light seems to be its tail-mounted driver with no extra channel to run BAT+ back or run the switch signal forward.

How does that work? Does it seem like something which might be useful for BLF designs?

I agree. I’d LOVE it if someone made a tail mounted e-switch driver that didn’t need the extra channel and sold it on Mountain Electronics. :heart_eyes: :heart_eyes: :heart_eyes:

No idea. I’m at the office right now and don’t have a way to test voltage. I charged it until the little red LED on top of the cell turned green.

I agree - it's fairly unique, but I think the UltaFire UF10 had the same design. Here's the UF10 driver from the tail:

I really like the UF10, same sort of tail e-switch, but much simpler UI. All I did was swap the LED/MCPCB,and maybe wires to get more output and added bypasses.We use it about every night with the dog.

Ohh, this is the PCB at the head, so there are some surface mounts but no smarts, I believe:

This is how I tested for amps:

tail assembly:

I went dedomed in the UF-10:

The pics on the UF10 were all from Aug 2016.

Mine sure wasn't. Happened on multiple cells - 30Q BT, PanaB BT, etc.

This info is disheartening.
I ordered one which will arrive tomorrow after the all clear was given.
Maybe I’ll get lucky with my sample but Not going to keep a flashlight that can’t be dis assembled to fix.

How does the flashlight operate with other cells?
Thanks

Keith

Actually, I think the fully-charged cell might be providing too much voltage to the LED.

After running the light another couple minutes on and off I notice that it no longer seems to blue-shift and dim. So the issue seems to occur with the fully charged cell.

Anyone figured out how to change the LED in the 18650s yet? From looking in the back of the head it looks like a press-fit plastic washer might be keeping the guts of the light in place.

Well, that's not press fit plastic. It's a black painted LED isolator glued to, what I think, is a shelf. I got the isolator ring off and it exposes threaded screw holes with screws in them from the top. Only way they could do that if the front end bezel comes off - suspect it's glued,very hard to see where.

Yeah, not the best UI and weaker output that spec'd, as stock. Looks difficult to mod, and this is all assuming you don't blow the LED -- ugh...

Maglite has tail mounted drivers on there XL lights.

Edit- but they run 3aaa in a odd carrier

Nothing magic done there. If the driver is completely in the tailcap it can work. think about that way that the tube is the led negative wire. The led positive is directly connected to batt+ and that is all. So the head only have a contact PCB which connects batt+ to led+ and tube to led-.the circuit is the same just the driver location changed in the light. The only drawback I see that is not good for high power lights because you can’t measure heat at led. If thermal sensor is in the controller it takes a lot of time to sense the heat. The only working option is timed stepdown. I hope I soon get mine and make an X-ray photo from head to see if there is any parts in there other than only a PCB.

How does the drivers MCU get batt+? I think that’s the magic she’s implying (seems magic to me too!)

Maybe it has some resistor parallel with led on the contact PCB in head to allow a little current.

Just look at the UF10 batt+ contact board above, and what I stated couple times earlier of measuring 51 ohms between batt+ brass button and the head housing, so there's current running through there. The UF10 has that hidden "thing" under the white hardened goop -- hhmm.

John from FB said: Mine turns blue and it gets quite hot. I've never seen one turn that color before and thought maybe mine was the only one like that. I'm going to see if I can get my money back. This is my first and last Folomov.

It's not sounding good...

I emitter swapped my Folomov 18650s today. :sunglasses:

This fixed the issue I was having with the emitter blue-shifting and getting dimmer with some fully-charged cells. Turns out the 219D just can’t take high current.

No pictures, but here’s how to emitter swap the 18650s:

  • The head looks like it’s in one piece, but it really isn’t. The bezel is the smooth portion ahead of the fins on the head. It’s just screwed onto the head. I applied 3M indoor stairway grip tape in a ring around the head and another around the fins and unscrewed. The bezel came off easily. There was no glue, but there is an o-ring.
  • With the bezel and lens removed, lift or tip out the smooth reflector to reveal the star.
  • The star is copper and is screwed onto the full shelf on the head with 2 screws. There is one wire connecting ground to the star. On the back of the star is a soldered post that directly contacts the top of the battery. The star also has 2 resistors on it. There is no other board at the head of the light. The driver is in the tail.
  • Desolder the negative wire from the star, then unscrew and lift out the star. Some thermal paste was used under the star, but more would be better.
  • The hardest part was heating up the star enough to remove the emitter without the post on the back getting out of position. I used a wooden clothesclip held sideways in a vise to grip the post on the bottom of the star, then used hot air reflow to remove and replace the emitter. I replaced it with a XPL V6 3D that I had laying around. I might end up replacing this later with an XPL HI for more throw.
  • I also added a copper disk onto the bottom of the post at the bottom of the star to allow flat-top cells to be used.

Firelight2

Thanks for the detailed de-construction!

Got mine yesterday and decided to try a burn-in at the medium setting, tail standing for a half hour.
Used a Sony 2600 laptop pull charged around 4.09.
Light got mildly warm but no problems.

Have not tortured the light at full voltage on turbo for more than a few seconds and have decided not too.
I Love the tint and have plenty of other pocket rockets that can be used for “shock and awe” but this one will just be used in an EDC setting and will leave alone.
That may very well be Un-BLF of me but do not want to give up on the good overall function of the flashlight at this point.
Will just use with a battery that is not full up and/or high amp.
If Folomov comes up with a solution, great, but for now it’s good to go.

It does not appear to have low PWM and has the perfect (for me) moonlight and also like the mode spacing.
Really wish it had a BLF A6 style driver with reverse mode switching but it has memory so can chose setting I like and leave it and still have access to Moonlight.
Also love the Soft Ramp Beacon, very nice touch.

Later,
Keith

Cool! Worked on a HT35 so didn't have time to work on the head. Back in post #45 I thought the bezel was removable. Does it do well on turbo/max now? Was wondering roughly how much amps. Probably the 219D is very low Vf so the amps can get way higher than with a XPL, but depends on the driver design.

Folomov - please make note, please verify.

Yes, replacing the 219D with an XPL fixed all problems with the light. It now functions perfectly at max power now on all 18650 cells that I’ve tried, including fully-charged VTC5A.