U2 Drop In with Good Battery Question

Hi everyone,

I have an UltraFire WF-502B, and I added a one-mode U2 emitter not too long ago. When using 3.7 V li-ion UltraFireBRC protected 3000mAh (the red ones) and black Soshine 2800mAh protected batteries I was detecting an extremely slight/occasional but consistent single "flicker" during output (barely perceptible, every 5 seconds or so).

Also, the emitter or switch seemed "glitchy" - sometimes emitter would come on low, and then turning it off and on would correct this, but I still saw that occasional single flicker.

Then I received six Cytac 2600 blue 18650 batteries (these are supposed to be good batteries). See chart from extensive testing: http://lygte-info.dk/info/Batteries18650-2011%20UK.html -- second from left in the photo, and 14th in the chart

Now my WF-502B operates fine when outfitted with these Cytac batteries -- no slight flickering. No low-light starts. Nice light output (actually, the same light output with Cytac batteries, but the operation of the light now is flawless).

However, could you knowledgeable folks tell me what might be going on here? With the "good" Cytac batteries this flashlight operates flawlessly. I have no clue. I realize your input will probably be conjecture, but I bet you'll be correct...

FYI, E1320 offered to rev up/rectify this flashlight, which I still might do. But with flawless operation with Cytac batteries I like this light much more now.

Also, the Cytac batteries take much longer to charge up fully compared to the other batteries I have...

Joe

Is there a difference between the lengths of the batteries? From what you have described it sounds more like a faulty switch or bad contact then a fault with the batteries. I have never heard of batteries causing flickering before.. but there is a first time for everything.

If I was you I would try and eliminate the different components until you can say with one it is with certainty. If you have a different p60 host try and swapping out the drop-in and see if the problem still occurs. Another thing to try would be too run the flashlight without the tail-cap (by shorting the negative of the battery to the flashlight tube) If the problem goes then it is most likely the tail-cap/switch.

EDIT: one more thing, what current is the drop-in pulling from the cell? It is possible that the Ultrafire and Soshine batteries are having a hard time delivering the current/ voltage the drop-in needs and one of the inbuilt circuits (either battery PCB or drop-in PCB) is producing the electrical "signal" (for want of a better word) because of this, which you see.

Hope this helps

That particular series of lights are prone to switch issues ...

From simply having a bad switch :

To the rubber switch boot placing to much pressure on the switch causing partial activation [ circuit breaking ]

To something as simple as the retaining ring being lose ...

Check the retaining ring , tighten if lose = Did this fix it ?

remove switch , trim the rubber nipple in the boot [ inside ] remove 0.5mm [ half a MM ]

Did this cure the problem ?

If not you may need to replace the switch ....

I was just looking at that review because I have never heard of Cytac batteries. The review says they are 69.5 mm long that is a long battery that might have something to do with your problem. Sounds like the ring holding the tail switch is loose follow old4570s advice to repair.

Oh well, I should be glad that using the Cytac batteries solved my issue with the 502B/U2 light, and not worry about why it's working well now.

But I suspect the problem may be what Manual Man said: "It is possible that the Ultrafire and Soshine batteries are having a hard time delivering the current/ voltage the drop-in needs."

My 6 new Cytac batteries work well in all my lights, so my UltraFire and Soshine batteries are now relegated to backup status.

Thanks - Joe

More likely to be that the switch retaining ring needs tightening and the longer Cytac is pushing it back to sufficient contact.

More likely to be that the switch retaining ring needs tightening and the longer Cytac is pushing it back to sufficient contact.

Ahh, okay, I'll take a look at that and see if that's something I can tighten.

Thank you.