Keeppower Protection Circuit Issue

[F89]

I've never had a protection circuit fail. While I use both types, I always use protected with two cell lights for obvious reasons.

 

[F89]

Still sounds like a contact issue to me.
The body is simply a conductive tube, so as long as everything is making contact and in working order (head and tail cap/switch) everything should work fine.
I get that it isn't though from what you're saying.

Check all the surfaces, threads, and connections are as they should be. Make sure everything is screening together firmly and that the head and tail cap are also clean and free of any debris that could obstruct them from mating cleanly.

 

[F89]

You mentioned using a little bit of steel wool when cleaning the threads/contact surfaces before. I wouldn't do that in future.
A rag, paper towel, tissue, whatever is fine with some sort of cleaning fluid or contact cleaner is all you need generally. I use isopropyl alcohol but even some diluted dish soap would be fine.
That said, I wouldn't use acetone either.

 

[md17]

You mentioned using a little bit of steel wool when cleaning the threads/contact surfaces before. I wouldn't do that in future.
A rag, paper towel, tissue, whatever is fine with some sort of cleaning fluid or contact cleaner is all you need generally. I use isopropyl alcohol but even some diluted dish soap would be fine.
That said, I wouldn't use acetone either.

There is not a speck of dust on this thing…it's brand new and no other cell types (cr123) or 18650 with a cr123 spacer, have any issue at all. I even tried loosening the tail cap to relieve some pressure on the batteries in case that was the problem and it still has an issue. I guess I'll only really know after trying a different type of 18500 and if that does not work, maybe exchanging the body for a different one.

 

[md17]

Still sounds like a contact issue to me.
The body is simply a conductive tube, so as long as everything is making contact and in working order (head and tail cap/switch) everything should work fine.
I get that it isn't though from what you're saying.

Check all the surfaces, threads, and connections are as they should be. Make sure everything is screening together firmly and that the head and tail cap are also clean and free of any debris that could obstruct them from mating cleanly.

So I actually tried the 2 18500 with a cr123 spacer in an md4 body and still had the same issue.

 

[Monocrom]

So I actually tried the 2 18500 with a cr123 spacer in an md4 body and still had the same issue.

That's unfortunate to hear.

 

[md17]

That's unfortunate to hear.

Well I'd rather have it be the batteries than the lights themselves, but I am just hoping the other model of keeppower 18500 work ok because protected 18500 seem limited.

 

[F89]

I've found the bore inside my old and new MD4 bodies is very accomodating. I still get battery rattle with 2x protected 18650. I actually put a couple of bands of electrical tape on two sets of batteries to take up the excess room.
In my MD2 I even use a sheet of paper cut to size to remove rattle using an unprotected 18650 (even a protected rattles a lot in there without the paper).
Try removing all the slop of the battery fitment with a roll of paper, then test.

 

[F89]

What's the length of the batteries including button top protrusion? Usually you can even look it up in their specs (you could compare the two even).

 

[md17]

What's the length of the batteries including button top protrusion? Usually you can even look it up in their specs (you could compare the two even).

The p1850c3 (which is what I have) is
52.40mm (L) x 18.50 mm (D) ±0.2mm

The p1850j2 (which is what I'll try next) is 53.50mm (L) x 18.60 mm (D)

 

[F89]

What's a CR123? About 34mm?
So about 102mm for three?

 

[md17]

What's a CR123? About 34mm?
So about 102mm for three?

I'm not sure exactly, but the 18500s definitely sit higher than the cr123. Gene is sending me the body extender kit to see if that fixes the issue with these cells, but the 18500 with md3 is such a widely used combo, so I don't see how I could be the only one with an issue if it's the cell size causing the problem.

 

[F89]

Yeah, it sounds tricky.

Safe to say that 2x18500 (protected) is longer than 3xCR123.

Did you try the sheet of paper?

 

[md17]

Yeah, it sounds tricky.

Safe to say that 2x18500 (protected) is longer than 3xCR123.

Did you try the sheet of paper?

Yes. It made no difference. I think it may actually be that there's too much pressure being put on the protection circuit, causing operational inconsistencies. Therefore a body spacer kit may fix the issue.

 

[F89]

Could be?
You did try loosening the tail cap right off also didn't you? That'd test the tube length/spacer theory to an extent.
Hopefully the spacer sorts out the issue.

 

[md17]

This is how the 2300 mah Keeppower 18500 sit in the md3. Does not seem excessive to me. Thoughts ? Should they sit lower?

 

[thermal guy]

Some of mine sit at that height and no problems here

 

[md17]

Some of mine sit at that height and no problems here

Then this really is a mystery

 

[thermal guy]

Then this really is a mystery

Yep. To me it still sounds like a contact problem but how I'm not quite sure.

 

[orbital]

+

Has it been mentioned to use a bit of electrical tape & tape the two 18500 together where they connect (just go around once)
maybe they are loosing contact just for an instant causing the problem.

Gotta try everything in troubleshooting


just can't imagine that two protected cells are to short for this setup,
unless the springs were crushed down from too long battery config...