Keeppower Protection Circuit Issue

md17

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When in series, the voltage scales up. Current draw stays the same. You'd need to run them in parallel (neg to neg, pos to pos) to double the current. Like in a soda can light.
The m62hot would be at around 7.2v and would be fine. But the hound dog would be over the rated draw
I presume he's using a power supply to get those number seeing as there's no way I know of to get 6 or 9 v. Maybe with those keep power regulated 3v cells
Ok so with this…the protected rcr123a terminate at 2.5v… this means they would cut off at around 5 volts being that two cells are used?
 

F89

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Ok so with this…the protected rcr123a terminate at 2.5v… this means they would cut off at around 5 volts being that two cells are used?
That's a pretty low cut off, but under load that's probably ok. I think the resting voltage of them would be around 3V or so at cut off. But of course you couldn't measure that as the circuit would have kicked in, they'd need to be reset on a charger to activate.

To answer your question, yes basically.

I still reckon what you're proposing isn't a reasonable option (2x16340 with a Hound dog XPL).
You'll get some pretty serious voltage sag, short runtime and generally crappy performance.
 
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md17

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That's a pretty low cut off but under load that's probably ok. I think the resting voltage off them would be around 3V or so at cut off. But of course you couldn't measure that as the circuit would have kicked in, they'd need to be reset on a charger to activate.

To answer your question, yes basically.

I still reckon what you're proposing isn't a reasonable option (2x16340 with a Hound dog XPL).
You'll get some pretty serious voltage sag, short runtime and generally crappy performance.
Understood. I am going to give it a shot with the m61hot though for the brighter low mode
 

F89

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Understood. I am going to give it a shot with the m61hot though for the brighter low mode
It'll be brighter on both modes very briefly but at a huge trade off in runtime and general performance.
You'd be far better off running the M61HOT off a single 18650.

If you were flat out set on running this head off two cells in an MD2 you'd be better off running 2x18350.

That said, if you're happy with the runtime etc then why not?
To put it in perspective, you could run a single CR123 sized light that performs similarly to your larger MD2 set up.
 

md17

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Well, I sent the picture of where the cells sit in the body to Gene. He said they are too high and should sit lower so the button top is visibly below the edge of the body. Additionally, he said he has not seen any 18500s sit correctly without the extender kit, so I am assuming I broke the batteries because I did not have an extender kit. But all my lights will now be getting an extender and battery bumpers.
 

bigburly912

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If you broke the battery you would more than likely see it. I've indented buttontops before and batteries ran fine for years.
 
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F89

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Half my batteries have some dents on either end and perform fine.

The Keeppower protection circuit is on the negative end and has a PCB type material rather than a metal plate if you follow me. Not sure if that has anything to do with it?
That said I have some Keeppower 16650 with dented button tops which are fine on the PCB end.
 

md17

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The only other explanation I can think of is the connection issue is because there's too much pressure on the cells and springs. The setup I was using is not an abnormal or crazy setup even without the extender kit imo.
 

md17

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This is a mystery just like the carpet being wet at Todd and Margo's house...

Well obviously something had to break the window! Something had to hit the stereo!
And Why is the carpet all wet, Todd? I don't know Margo!

Tis' the season
 

orbital

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+

More joy w/ 18500 (top light) buttontop 18500 needed
can be had for $58 total cost today @ neals using BLACKFRIDAY coupon code, make sure you order with the extensions!

don't pass on that light, at that price


1700844444259.jpeg
 

vicv

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More joy w/ 18500 (top light) buttontop 18500 needed
can be had for $58 total cost today @ neals using BLACKFRIDAY coupon code, make sure you order with the extensions!

don't pass on that light, at that price


View attachment 52983
I always like those lights. I will have to get one sometime. Question though. And if I am wrong, then understand I'm not making a statement here. Isn't Neil's gadgets a place where a bunch of people got ripped off or am I mixing that up with somewhere else?
 

orbital

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I always like those lights. I will have to get one sometime. Question though. And if I am wrong, then understand I'm not making a statement here. Isn't Neil's gadgets a place where a bunch of people got ripped off or am I mixing that up with somewhere else?
+

Years ago, nealsgadgets.com lacked great customers service. They fixed that.
In my last several orders, it's been all good & somewhat fast delivery.

Just today I got something from them, took about 7 business days,,, not terrible at all.
 

md17

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Ok, so I got the Md body extender kit and it still did not fix the issue with the pair of problematic 18500 cells on the md3, but seems to work well with the others.

Anyone who has used the extender kit, if both rings are used, that means the o ring has to be used on the higher slot correct? Unless I'm doing something wrong, there's not way of getting the lower o ring back on with both extender rings installed.

This is how I installed it with a pocket clip on an MD4 body and I like it.
 

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md17

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So, the spacer still did not fix these 4 18500 cells. Started getting flickering after an extended runtime with the hound dog. Shouldn't it just cut out once the protection circuit kicks in?
 

thermal guy

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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.
 

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.
What's odd is that it is ok until about 3v then it starts flickering.
 

knucklegary

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Malkoff's will jump between hi/lo if head is not screwed in/out all the way..

I will intentionally keep head in that position to switch back and forth, using one hand with thumb/forefinger on head.

OP,, can you show a vid of it doing that flickering with flashlight stationary, sitting by itself ?
 
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