REALLY weird Jil flupic/Seoul P4 behavior!

[Dan C]

I have a really odd problem and am looking for ideas........

I have two Jil's, one running the standard body with a RCR2 batt, the other with a CAB body with 14500. I just upgraded both with Goldserve's Flupic/Seoul P4 sandwiches.

I immediately noticed that the beam on one of them, when running on high, would literally turn from white to blue before my eyes, also dimming noticeably, within no more than 20 seconds. It was fine on a lower setting, staying nice and white. I confirmed this with a light meter, it would start out reading 1600 or so lux and plummet to the 1000 range within 15-20 seconds.

Now the weird part. I swapped heads between the 14500 and CR2 bodies, and whichever head was on the 14500 body would exhibit this behavior, turning angry blue in seconds!

What the hell is up with that??

Dan C

 

[Pumaman]

sounds like its being driven too hard without proper heatsinking. it can happen when you put too thick a layer of AA epoxy between the emitter and the heatsink(to isolate the slug polarity). this is just a guess on my part tho... contact goldserve, he may have more insight.

 

[kabkbak7321]

I have the same prob on my l2p on 1 3.7 lith with Jil flupic/Seoul P4.It will go blue in 10-15sec,
I asumed That I do not have a good thermal path from emmit to base
with the thermal epoxy.Any thoughts would be nice.
Thanks,kabkbak7321:thanks:

 

[Dan C]

That was my thought also, but it makes no sense that when I switch the head to the RCR2 body the problem disappears?

Dan C

 

[goldserve]

Hrm...it does seem like a heatsinking issue. The light gets driven very hard and with 14500s, the battery is able to hold +1000ma currents where as the RCR2s die down under 1A. I think the seoul leds have like a critical point when they turn blue.

 

[Dan C]

Hrm...it does seem like a heatsinking issue. The light gets driven very hard and with 14500s, the battery is able to hold +1000ma currents where as the RCR2s die down under 1A. I think the seoul leds have like a critical point when they turn blue.

Interesting. When I set it to level 10, everything is fine. On max, it starts wigging out. What's the drive level difference between 10 and max? The brightness difference is practically unnoticeable. I'm inclined to just leave it on mode 3, level 2 and 10 (or less), and live happily ever after.

Dan C

 

[goldserve]

Level 10/10 is around 700ma and burst can be 1A. I always drive my seouls at no more than 850ma because there is a declining returning going above 750ma. As you have noticed, 750ma and 1A will not be a noticeable difference.

 

[Norm]

My Fenix L1T with Flupic did the same until I really seated the LED hard into the heatsink no arctic alumina just heatsink compound seems to be fine now. Just hope that the initial minute or so running angry blue didn't permanently damage the P4.
Norm

 

[WildChild]

See this link:

http://www.molalla.net/~leeper/seoulmy.htm

Some tests made with Seoul LEDs! He got the angry blue problem too!

 

[PEU]

maybe the batteries have different internal resistance, that may explain it


Pablo

 

[vortechs]

Dan C,

Can you measure the current draw with each battery to see if the current is higher with the 14500 cell?

Does the problem with the blue tint go away when the 14500 cell voltage drops or does it still occur even when the 14500 cell voltage has fallen to 3.6V (nearly discharged).

I haven't had any problems with running my JIL's that goldserve modded with Seoul P4 LED's on RCR2 Li-Ion cells. I will have to try them with a 14500 cell.

 

[Dan C]

Those are some things I'll check out when I get the chance. That's gotta be the explanation..I"ll post an update when I get home to test it.

Dan C

 

[vortechs]

I tried my two Seoul-modded JIL heads on a CAB body with a AW protected 14500 Li-Ion cell (at about 3.95V) and didn't see either of them turn blue during a couple of minute run. I'll try a longer run at higher voltage when I have time.

 

[Dan C]

OK, here's some numbers. The 14500 (AW protected) measured 4.24v, and the RCR2 (AW protected also) went 4.07v off the Nano charger.

Current draw on max using same head:

14500, between 1.6 and 1.7 amps.
RCR2, right at 1 amp.

On level 10, it draws 800ma on the 14500, and that's where I'll run it from now on.

 

[vortechs]

I tried my two Seoul-modded JIL heads on a CAB body with a AW protected 14500 Li-Ion cell (at about 3.95V) and didn't see either of them turn blue during a couple of minute run. I'll try a longer run at higher voltage when I have time.

I charged the AW protected 14500 cell up to 4.16V on a DSD charger. With the cell at this voltage I observed the 'angry blue' effect that Dan C described from one of my two Seoul-modded JIL heads. The Seoul LED in the other JIL stayed white at the higher voltage (for a couple of minute run). The JIL that developed the blue tint would only show the blue tint in the Maximum (Burst) setting; switching to another level would return the tint to white. I didn't have time to check the current draw, but I would guess that a difference in the amount of current the LDO's in the FLuPIC's in the two different JIL's allow to the Seoul LED in Maximum mode is why one of my JIL's exhibits this behavior and the other doesn't. The solution seems to be straightforward, just avoid using the Maximum mode when running with a fully charged 14500 cell.