Keeppower Protection Circuit Issue

md17

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i Have many malkoffs and many 18500. When protection circuit kicks in the light shuts off. None of mine flickers on low voltage and I have done many runtime tests.
When you performed those tests, was it with protected rechargeables or primaries because I just tried it with primaries, and I have no flickering and a very long taper on the hound dog XPL
 

vicv

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3 primaries or 2 18500 will perform the same. Only runtime will be different. The light doesn't know where it's getting its power from. Both setups provide more voltage that the led needs. So it uses a buck driver to reduce to 3 volts.(I presume this is using a 3 volt led. But even if not it'll be a boost driver instead, same incoming voltage).
 

md17

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3 primaries or 2 18500 will perform the same. Only runtime will be different. The light doesn't know where it's getting its power from. Both setups provide more voltage that the led needs. So it uses a buck driver to reduce to 3 volts.(I presume this is using a 3 volt led. But even if not it'll be a boost driver instead, same incoming voltage).
The hound dog xpl input voltage is 5.5-12v. I'm interested in the reason why it will flicker with protected cells but taper with primaries.
 

vicv

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It will taper with lithium ion batteries as well. Very quickly though, because the cells will be completely dead. But there's something wrong with yours which is causing the flickering. That's the best I can think of because because the light doesn't care.
 

md17

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It will taper with lithium ion batteries as well. Very quickly though, because the cells will be completely dead. But there's something wrong with yours which is causing the flickering. That's the best I can think of because because the light doesn't care.
Something wrong with the light or the battery?
 

thermal guy

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It will taper with lithium ion batteries as well. Very quickly though, because the cells will be completely dead. But there's something wrong with yours which is causing the flickering. That's the best I can think of because because the light doesn't care.
It won't taper with protected lithiums. It's an immediate off
 

Monocrom

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Hot flashes, light flashes…basically the same thing.
Naw.... Women are much more dangerous if you don't handle them right during PMS time. Worse thing a flashlight can do is explode in your face. Tame, by comparison.
 

md17

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Ok. Here is the conclusion:

After buying a new charger and 3 different sets of protected Keeppower batteries, testing them in 3 different lights with all different tail caps and bypassing the tail cap for testing as well as using the Md extender kit,
I can't explain why one set of 18500's don't work and shut off randomly. It's gotta be a bad set of batteries.

As far as the rest of the batteries that were causing the flickering…I emailed Gene and he said flickering is normal and will occur when voltage is below 3.2v. There may or may not be a small taper, but more than likely the light will flicker or just shut off. This is specifically referring to the Hound Dog xpl, but it happened to me with m61hot v2 and the newer m61w also.

Thanks to everyone for helping me through this emotional time I couldn't have done it without you.
 

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vicv

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Ok. Here is the conclusion:

After buying a new charger and 3 different sets of protected Keeppower batteries, testing them in 3 different lights with all different tail caps and bypassing the tail cap for testing as well as using the Md extender kit,
I can't explain why one set of 18500's don't work and shut off randomly. It's gotta be a bad set of batteries.

As far as the rest of the batteries that were causing the flickering…I emailed Gene and he said flickering is normal and will occur when voltage is below 3.2v. There may or may not be a small taper, but more than likely the light will flicker or just shut off. This is specifically referring to the Hound Dog xpl, but it happened to me with m61hot v2 and the newer m61w also.

Thanks to everyone for helping me through this emotional time I couldn't have done it without you.
So each cell 3.2v so 6.4v and it will flicker? So it should do it when primaries are at a total of 6.4v. But you said it doesn't happen with primaries
 

md17

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So each cell 3.2v so 6.4v and it will flicker? So it should do it when primaries are at a total of 6.4v. But you said it doesn't happen with primaries
Correct. But that is 3.2v each cell measured without sag. Why it doesn't flicker and have a long taper on primaries? I do not know.

Maybe one of the 2 cells already had the protection circuit kick in, so it's actual only running on one cell?
 
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