Your thoughts on Malkoff MDC AA

[RWT1405]

No, they were simply the same 'label' (brand) Li-ion cells, of nominal '3.6/3.7V rating. They were my only experience with their cells.

The cells fundmentally lacked the performance capabilities required to properly operate the light they were being sold to work with (which was the original S1). It wasn't a 'good look';-) It needed a better cell, which is what mine got, and it worked as advertised with cells from a different manufacturer.

Ten years is a lifetime in Li-ion cell tech, and I'm their situation is different now - it must be.

Ahhhh.... I think I have it now...

You had problems with Olight batteries

That is good to know, and I will keep an eye on them

 

[Schokokeks]

Ahhhh.... I think I have it now...

You had problems with Olight batteries

That is good to know, and I will keep an eye on them

I recently got one of these 2.4V batteries to run in my Peak El Capitan. It started behaving REALLY goofy after about a day.
I've tried it in other AA lights, and when I cycle modes, it seems to cut out. Normally, I click through low->med->high, but when using this, it seems to just...shut off, and then I have to restart the cycle.

That's with dual fuel lights, too, so they should be good from 1.2V-4.2V.

So far, I've only really liked the Perun 2 Mini headband...I get the free AAA lights to give away, but this 2.4V battery has been really goofy. I don't know if this is normal, or if I got a dud. I might reach out to them and see if their CS is any good.

For what Olight charges, I expect more...so, I'm still on team "Olight hater."

 

[aznsx]

I might reach out to them and see if their CS is any good.

This is speculation on my part, but I think there's a strong possibility that they would inform you that they do not support the use of that cell in any other product besides the one it's designed / recommended for (I5R?). That said, I wouldn't put money on any bet where they're concerned. I already lost a couple of bets with them 10 years ago;-)

That voltage may put some lights right in the middle of an input voltage 'dead / limbo zone' (which they are never 'supposed' to see) and that the circuitry might not react to well / predictably to. I can imagine that.

EDIT: Do these cells use a switching regulator / power supply circuit similar to those 1.5 V Li-ion cells that have proliferated lately?

 

[Schokokeks]

This is speculation on my part, but I think there's a strong possibility that they would inform you that they do not support the use of that cell in any other product besides the one it's designed / recommended for (I5R?). That said, I wouldn't put money on any bet where they're concerned. I already lost a couple of bets with them 10 years ago;-)

That voltage may put some lights right in the middle of an input voltage 'dead / limbo zone' (which they are never 'supposed' to see) and that the circuitry might not react to well / predictably to. I can imagine that.

EDIT: Do these cells use a switching regulator / power supply circuit similar to those 1.5 V Li-ion cells that have proliferated lately?

That was actually my very first thought; the moment I mentioned I wasn't using it in one of their lights, I assume they're going to tell me I'm SOL.

And, I am also wondering if it has something to do with the circuitry, like the 1.5V cells. That's my assumption.

 

[aznsx]

That was actually my very first thought; the moment I mentioned I wasn't using it in one of their lights, I assume they're going to tell me I'm SOL.

And, I am also wondering if it has something to do with the circuitry, like the 1.5V cells. That's my assumption.

Yeah, if it perhaps generates 'noise', that can always be a (very negative) factor in most any electronics. I don't know the design of this cell, but...

That aside though, it seems to me that 2.4V is also a sort of value that falls in the gap between ranges of the nominal / expected voltages of all the other 14x50 cells I'm thinking of(?). I think Eneloops are in the ~1.2V range(?), Alkalines ~1.5(?), and Li primaries topping out ~1.7x(?). The lower limit of what I consider a valid, healthy, functional Li-ion of most chemistries (LFP aside) is 2.5V. 2.4V falls into an ambiguous / undefined zone (1.8-2.5V), and that could in and of itself cause operational anomalies in certain lights, depending on their specific design. If I were specifically picking a voltage that might not work well in a bunch of lights, it would be in that range, and probably near the top of it so it could sag some and still stay in that range. Nothing else I can think of should 'expect' to see that input voltage.

'And you may ask yourself': Was the choice of a voltage in the ambiguous zone a matter of engineering happenstance, or one chosen because of that fact?;-)

 

[Schokokeks]

Well, it behaved REALLY poorly in my dual fuel Convoy, and so I was thinking along the same lines as you, with it "neither fish nor fowl" in voltages for the driver.

But, in the Peak? That's really weird, cause - as far as I know - that's just always direct drive.
Which then got me thinking, USUALLY dual fuel is boost for below 3V, and then direct drive above, so it SHOULD still work at 2.4V just fine; in fact, it should be MORE efficient. I know SOME are boost/buck, but still, that BOOSTS to 3V, and Buck down to 3V, so this SHOULD fall in a good goldilocks zone.

The only thing I can think is maybe the protection circuit has something goofy going on, and is tripping.

 

[aznsx]

The only thing I can think is maybe the protection circuit has something goofy going on, and is tripping.

If you found a way to trip the protection circuit on that cell(??), I'd say you got lucky. I'd consider that preferable to blowing up a light. I'm having trouble following this thread, so with no dog in this hunt (or horse in this race), I placed a couple of small bets, and am content to sit in the stands and watch the race now. Time will (or may) tell;-) Cheers!

 

[dc38]

Well, it behaved REALLY poorly in my dual fuel Convoy, and so I was thinking along the same lines as you, with it "neither fish nor fowl" in voltages for the driver.

But, in the Peak? That's really weird, cause - as far as I know - that's just always direct drive.
Which then got me thinking, USUALLY dual fuel is boost for below 3V, and then direct drive above, so it SHOULD still work at 2.4V just fine; in fact, it should be MORE efficient. I know SOME are boost/buck, but still, that BOOSTS to 3V, and Buck down to 3V, so this SHOULD fall in a good goldilocks zone.

The only thing I can think is maybe the protection circuit has something goofy going on, and is tripping.

lithium ions SHOULD go as low as 2.9V, but CAN go down to 2.7~2.8V before dropping into the danger zone. They can also go as high as 4.35V, but most protection circuits and chargers limit them to 4.2V.

As others have speculated, the Olight 14500 is set to run 2.4V, which is BELOW the minimum safe voltage for a standard Liion, but is way above the max voltage of a disposable, which should be the lithium primaries at about 1.84V. So it's probably treating the 14500 like 2 partially depleted eneloops, but the protection circuit on the battery cuts before the eneloops or primaries would be too low to run. So you're probably losing a ton of runtime on the lower end.

Here's a visual:
Light denies Max below 3.7V
2 eneloops
[1.6V empty--------------2.8V Full]
14500 Olight 2.4V buck protection
[2.7V empty-------------4.2V Full]
light runs until dry at 1.6V, but protection circuit for 14500 kicks in at 2.7V CELL voltage, even if the applied voltage is 2.4V.