A possible idea for all those interested about Fenix on Li-Ions

Hi,

It seems like the same question with regards to "Can my Fenix XXX be safely run on XXX rechargeable lithiums with no long term damage because the light is getting pretty hot, etc,etc?"

Obviously, no-one really wants to be the first to give it a real test and blow their new toy up. For example, most people have tried their LOD-CE on 10440 (myself included) but only for relatively short time spans - the longest I've seen on CPF is 5mins 30seconds.

Now, what about if everyone who was interested about a particular light, eg a LOD-CE on a 10440 was to paypal a dollar or so to an individual, who would then purchase the light and then just run it continously on the various levels with a 10440. When the 10440 starts to run down, pop another one straight in and let the test continue. The test could run for hours on end, or until the light died. Then we'd have our answer.

This way, no-one blows their own light, and for the sake of a dollar or so, potentially saves them their own light too as they won't have to try it. Maybe we could even get a discount on the purchased light, as it's for research purposes.

This may be a really rubbish idea for any number of reasons that I haven't thought of, but I'd love to know your thoughts on the matter.

Cheers,

Face

That would only tell us how long only one light would survive. While perhaps better than no information at all, it still doesn't tell us how long our particular light would survive. There might also be degradation of components including but not limited to the LED well before complete failure.

I've been experimenting with adding a small resistance in series with the battery when direct driving lights from low impedance Li-Ion cells. When I do this with my L0D CE running on a 10440, it doesn't act like direct drive -- the resistance required to bring the current down to somewhere around the LED maximum (around 0.82 ohm) is much greater than the resistance of about 0.33 - 0.39 ohm which would be required if the LED were truly being directly driven. So the circuit is apparently still trying to boost the voltage from the cell despite its already high voltage. To my mind this isn't good at all, and I'll use some other way to impress people with small bright lights. But each to his own.

c_c

It`s a good idea...I wonder if 7777 would be interested in doing this. That way he could see first hand what the damage looks like, so if folks try to return a light that had suffered damage from overvolt he would know and could decline replacement.

I would hate to see people taking advantage of his generosity and Fenix.

I ran my L0D CE from a fully charged Lithium 3.7v cell to flat, on high, in one go, with no problem. Held it in my mouth while clearing out the shead two nights ago.

Well, there we go, we know that it looks like it can take at least 1 full cell then.

So what sort of stuff did you find in your shed that you'd forgotten about / thought you'd lost?

I ran my L0D CE from a fully charged Lithium 3.7v cell to flat, on high, in one go, with no problem. Held it in my mouth while clearing out the shead two nights ago.

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Hero # 1 :goodjob:

Face said:

So what sort of stuff did you find in your shed that you'd forgotten about / thought you'd lost?

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Probably some of his teeth, just after the light blew up.

^ ^

I've used a 14500 (from AW) in my L1D-CE until dead as well without problems. It doesn't even get very warm. It sure is bright though.

I'm personally not too worried about it. If it quits on me, I'll get myself another, or a JetBEAM which regulates it. I think I'll probably see 1000 cycles on my battery before the LED dies. (1000 cycles almost equals 1000 hours, are we really reducing the life THAT much?)

Face said:

So what sort of stuff did you find in your shed that you'd forgotten about / thought you'd lost?

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The baby was having an un-settled evening and so I decided to re-arrange the shed at the bottom of the garden leaving the missus to take care of the newborn.

I agree with ziggggggg... above that it didn't get particularly warm. Perhaps to a new member it would seem that way but compared to a L0D with 3W Luxeon or an Orb NS it wasn't hot enough to worry about. ( Or to take out of my mouth.)

I just ran my L1D CE flat from one AW's protected 14500 3.7v straight of the charger. I got exactly 1 hour 32 seconds runtime on High until the protection kicked in.

The L1D CE got pretty hot, though not as hot as my L1T one same batteries. Very nice I think, 1 hour runtime, not bad at all...

Originally posted by Zigziggityzoo:I've used a 14500 (from AW) in my L1D-CE until dead as well without problems. It doesn't even get very warm. It sure is bright though.

I'm personally not too worried about it. If it quits on me, I'll get myself another, or a JetBEAM which regulates it. I think I'll probably see 1000 cycles on my battery before the LED dies. (1000 cycles almost equals 1000 hours, are we really reducing the life THAT much?)

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Originally posted by whc: just ran my L1D CE flat from one AW's protected 14500 3.7v straight of the charger. I got exactly 1 hour 32 seconds runtime on High until the protection kicked in.

The L1D CE got pretty hot, though not as hot as my L1T one same batteries. Very nice I think, 1 hour runtime, not bad at all...

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Now we know that a single L1D-CE won't blow up with a run on high from a Li-Ion battery. That still doesn't answer the long term effect on the led from doing something like this regularly. Also, Chevrofreak did some tests on current drain on Li-Ions of both the LOD-CE and the L1D-CE. He found the current drain on turbo on the L1D-CE to be 0.69A, if my memory serves me, and the current drawn on the LOD-CE to be 1.3A. So, it seems reasonable from this to infer that the Li-Ion cells are safer on the L1D-CE on turbo than they are on the LOD-CE on high. I believe he found that the draw on the LOD-CE was well below 1A on medium and low, which would make it safe at those levels. Personally, I would be a bit nervous about running the LOD-CE on high regularly with Li-Ion. I'd especially keep it away from my face!

whc said:

I just ran my L1D CE flat from one AW's protected 14500 3.7v straight of the charger. I got exactly 1 hour 32 seconds runtime on High until the protection kicked in.

The L1D CE got pretty hot, though not as hot as my L1T one same batteries. Very nice I think, 1 hour runtime, not bad at all...

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A question, do you know how long runtime you had left on the L1D(any level) when the regulation kicks in (3,0V?). Or is the battery more or less then when that happens?

Lobo said:

A question, do you know how long runtime you had left on the L1D(any level) when the regulation kicks in (3,0V?). Or is the battery more or less then when that happens?

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Don't know for sure when the protection kicks in on the batteries from AW, I think it is about 2.7v, so that gives me about 0.3v runtime with regulation (if the regulation kicks in at 3v). I don't notice any difference in light output on turbo mode, but when the 14500 have bean used some time, and dropped some voltage, the low mod is notable lower (non of the other levels are working though, only low).

The protection in AW's 14500 kicks in before I can notice any dim in the light output, would be nice to see when to change the batteries, but it just shuts off sudden .

chevrofreak did runtimes tests on the Fenix L0D-CE with all sorts of batteries, including 10440. It did a bit over 10 minutes to 50% on high mode.

https://www.candlepowerforums.com/threads/152223

I often wonder how the circuit will handle being overdriven to the max after a period of time