Keeppower Protection Circuit Issue

md17

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Yep if the protection circuit kicks in, it comes down like anvil. Hate to beat a dead horse but that's still looks like some kind of connection problem.
But it's dependent on the battery voltage. There's no issue when the battery is full. Wouldn't a connection issue happen despite voltage?
 

vicv

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Have you tried different cells? From what I can remember, it does this with two different sets of 18500. Looks to me like it's the driver acting up when getting around 6v or lower. The lvp on the cells should just shut off. I think it's a problem with the driver
 

md17

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Have you tried different cells? From what I can remember, it does this with two different sets of 18500. Looks to me like it's the driver acting up when getting around 6v or lower. The lvp on the cells should just shut off. I think it's a problem with the driver
I am trying to run some other cells in an md4 down now. But the first set of 18500 I had issues with will only turn on occasionally now with multiple different lights and tail caps.

The set that flickers works ok until they're around 3 volts each. I will test with other lights in a bit.
 

md17

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The only light I've tested for the flickering was a hound dog xpl, but I had issues with the first set of 18500s not working when fully charged with an m61hotv2, hound dog xpl and an m61w
 

md17

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Are the buttons on the cells smashed in? Flatten?
No. They're two weeks old. Just tested the cells that get screwey around 3 volts with an m61w and I also get flickering. I'm starting to think there's a defective set of lvp circuit boards or something. I don't know much about those, but these batteries look perfect.


Light flickers for a few seconds then shuts off

 

ilikeguns40

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Just thought I might add; I had flickering issues running a protected keeppower 14500 in a AA body paired with MDC head. They were too long and put too much pressure on both tailcap and driver spring
 

md17

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Just thought I might add; I had flickering issues running a protected keeppower 14500 in a AA body paired with MDC head. They were too long and put too much pressure on both tailcap and driver spring
How low were they sitting? because I used an Md body extender kit and now the batteries sit nice and low.

And what did you do to solve your issue with flickering ?

IMG_5181.jpeg
 
Last edited:

ilikeguns40

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My 14500 in the AA body sat way above the threads. Unfortunately there is no extender for the AA MDC body. I believe Gene designed that body around a standard sized AA Primary battery
IMG_9965.jpeg

IMG_9966.jpeg
 

F89

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Even without the extender the batteries were still at a reasonable height.
 

md17

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Yes. I can confirm that bypassing the switch still causes flickering, but the first set of cells does seem to be pressure dependent whether they work or not.
 

bigburly912

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So many pages. Is there a reason you don't want to use something besides 18500s?

Genuinely curious. Not dogging ya for your choice.
 
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