Strange problem with Panasonic NCR18650's across 5 different flashlights.

LED Flashlights – General Info 18650 Flashlights
1

I bought two separate batches of Panasonic NCR18650’s from HKE on ebay. And across 5 different flashlights, when the battery is fully charged, the blinking mode will not work.
If I leave the light on high for 5-10 minutes, and start cycling the modes, I can eventually get the light to work across modes.

Some details about the batteries and lights:
Each light is a regulated light.
Both batches of batteries are protected (8 cells, total).
All batteries were charged to 4.2 volts on a SYSMAX Intellicharge i4 JETBeam Nitecore charger:
This same charger charged a pair of 26650’s for use in a Trustfire A8, and both batteries (Trustfire 5000’s) work perfectly when fully charged.

Five flashlight types:
Four random single battery XML-T6 flashlights.
One one of these XML-U2 lights XML-U2 .

Out of the 5 lights, including the XML-U2, only one of them worked across all the modes with a fully charged battery. This one: Fandyfire 2130
And it only did that once. The second time I charged the battery, it did just like the rest of the batteries.

Does anyone here know what the issue is with these batteries/lights?

Is there a fix other than partially discharging the batteries after each charging?

2

That is strange.
Can you list the lights… all 5 of them?

Can you remove the front bezel and power the light without the reflector? (eliminate the possibility of a reflector short). Does the problem persist?

Can you loosen the tailcap or front “shoulder” are a of the light? (eliminate the possibility of a cell-crush condition). Does the problem persist?

3

What is the voltage of the batteries when they come off the charger ?

4

EDC XML-U2
FandyFire 2130 XML-T6
FandyFire HD2011 XML-T6
FandyFire A10B XML-T6
UltraFire C6-T60 XM-LT6
I actually bought two of these, and they both do the same thing.

These are all different body designs, and even different manufacturers, so I can’t imagine the lens could be shorting on them all. But I took one off of the UltraFire light, and it didn’t help.

As far as the cell crush situation goes, the lights work if I run the battery on high for 10 minutes or so. So it doesn’t make sense to me that it’s the battery being too tight, although I did try with the 4 styles I have here (one of them is at work), with no luck.

.

5

4.2 volts.

6

Pretend your audience knows nothing about flashlights, and describe precisely how you’re trying to cycle through modes.

7

I'm pretty sure your protection circuit is tripping.

At full battery charge, the strobe must be pulling very high current in short pulses. These spikes, though in short bursts, triggered the over-current protection.

Once the battery has been used for a while, the voltage & current drops just enough to evade tripping the circuit.

If any, this confirms your batteries are in good condition and can deliver real amps

8

Pulsar, if that was true then you would have to put it back in the charger to reset the protection. My theory is a connection problem somewhere.

9

Unlike overvoltage(OV) or undervoltage(UV) protection, overcurrent(OC) protection has the option of deadtime control length.

OV needs the V to rest to below threshold before FET turns on again.
UV needs charger to be connected AND V to rise above hysteresis voltage before FET turns on

OC can have deadtime length - (e.g 2 second) FET off before it turns on again. It's up to to the circuit designer.

That's why I think it's possible OC protection kicks in and remains off while the strobe is in effect.

10

But why would the pulse of a strobe pull more current than the maximum that the driver lets through to the LED? The XM-L version of the EDC from IO that the OP has is regulated at 2.45A.

11

same batteries same charger no problem in all my lights

12

I find this all hard to believe. Five different flashlights with eight different batteries.
The odds of this abberation happening is mathematically astronomical.

13

The batteries are the same. Even though purchased on two occasions, it's still possible to get the same batch with the same extra sensitive overcurrent protection circuit.

If I were you (LED A stray), I would set the charge to 4.1V for these batteries and get it over with. I believe that should solve the problem. You probably lose a couple hunder mAh, but on the plus side, gain some good battery life cycle.

14

By pushing the end cap button one click at a time.

It also doesn’t work if I do the partial push to cycle the modes.

15

This did occur to me, although I was hoping there would be a simple fix for it.

So let’s say this is the case, then… is there a way to avoid this with the next batteries I buy? The flashlight is already regulated, do I really need protected batteries?

16

Good point, they probably do production runs well into the thousands for these.

I’ll have to see what voltage i’m getting when the charger hits the 2 out of 3 lights. Maybe i’ll get lucky and that will be the “just right” point.

Or maybe i’ll be doing voodoo hex curses on the designers of these protections circuits. J)

17

Is it only strobe that doesn’t work, or are you unable to switch to low modes as well? You can’t cycle at all, right?

18

That has completely varied. On a couple of them, I get high and low. And the rest of them only have high until the battery winds down a bit.

19

Just to be clear, you’re saying that on some lights you can cycle to lower modes, but you can’t reach strobe on any of them?

Do your lights ever turn off when trying to cycle modes?

Can you get them to cycle by bypassing the tail switches completely?

20

This has happened before with Intl Outdoor blue, their overcurrent protection was set at 3A and caused all sorts of trouble. They changed it to Black version with much higher current trip protection.

https://budgetlightforum.com/t/-/5657


You could, with proper care, remove protection circuit from one battery to confirm. If that battery runs without problem at full charge, then this theory is proven.

As for protection circuit, you seem to be:

1. Charging with a good well-known charger
2. Using original battery from Panasonic (one of the safest)
3. Running single battery lights only

So IMO you're ok to use unprotected battery.