Has anyone ever?...

RedForest UK

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Okay, yesterday i tried a 10440 li-ion cell in my itp a3 for the first time, and while i have heard people warning about fried circuits and thermal runways i know that i'll never be able to go back from this, it must have been putting out at least 150lumens! :devil:

I know the risks, and will try never to have it on in high mode for over two minutes, but I'm still worried about potentially destroying what is even without using a 10440, a really good light. So, my basic question is has anyone ever actually fried/destroyed their itp from using a 10440 battery, and if so, just how hard were you running it?
 

RedForest UK

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:anyone: Well, i'm guessing no news is good news on this one? Does no-one want to warn me of blowing my hand off or anything?
 
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RedForest UK

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Yeah, that was one of the first things I read. But the way i interpreted it was that he just didnt want to do a runtime test on it, which is understandable, as that would have meant running it non-stop for maybe 30/40minutes. I've personally had it on for almost 2 minutes and it was only slightly warm to the touch, although it was outside in the cold..
 

Jay R

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Not got an ITP but I have used 10440 cells in every 'L' range Fenix AAA light they made and my Maratac. I've run each light from full battery to 'empty' without switching off many times and not a single one has failed yet.
 

RedForest UK

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In a maratac? Thats good, they're pretty much itp clones circuit wise from what i can see.. So, you havent had any problems at all? Could you say how long you got on full power on the maratac from full to 50%? :poke: Thanks lovecpf
 

Jay R

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Only got the Maratac in the past few weeks but it's run on high for around 8-12 mins ok. Mind you, you have to hold it firmly round the head to stop it heating up too much.
 
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DM51

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You are very unlikely to blow your hand off. However, if you persist in using a battery with a higher voltage than the light is rated for, you will damage the LED. It may continue to work for half an hour, it may last 20 hours - it is not possible to predict how long. The light from the LED will eventually start to turn angry blue/purple, then it will fade, then eventually the LED will turn brown and fail.

This has happened numerous times with members here - for example with the Amilite T3. Amilite clearly stated that the T3 should NOT be used with a cell >3.0V, but people still went ahead and used 3.7V Li-Ions instead of primaries.

BTW, you probably won't be doing your 10440 cell much good, either.
 

RedForest UK

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Sorry if this seems like a stupid question, but why exactly would using a higher voltage battery shorten the life of the led in this light if the same voltage can be put through the same led in say the fenix tk10 with no issues whatsoever?
I know there is probably a good reason, but i can't see any problem myself other than the potential heat buildup at the led. :shrug:
 

Black Rose

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So, my basic question is has anyone ever actually fried/destroyed their itp from using a 10440 battery, and if so, just how hard were you running it?
Not with my iTP A3's (I only use NiMh and lithium primaries in them), but I did eventually do some damage to the driver in a Romisen light by running 16340 Li-Ion cells in it.
I think it took a total of about 4 hours of extended use (run time tests with different 16340 cells) before the problem showed up.

It would no longer produce a decent amount of light when used with CR123A primary cells.
When using a Li-Ion cell it ended up direct driving the LED (Cree P4).
 

easilyled

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Sorry if this seems like a stupid question, but why exactly would using a higher voltage battery shorten the life of the led in this light if the same voltage can be put through the same led in say the fenix tk10 with no issues whatsoever?
I know there is probably a good reason, but i can't see any problem myself other than the potential heat buildup at the led. :shrug:

Because the Fenix Tk10 probably has a hundred times or more surface area with which to draw the heat away from the led.

The smaller the light, the less the ability to do this, therefore the hotter the junction temperature (which is what reduces the life of the led).
 

gbelleh

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I've used a 10440 in one of my Maratac AAAs for the last 7 months. It's been fine, but I haven't run it on high for more than about 1 minute at a time. Medium is plenty bright for most tasks anyway. If I need more light, I almost always have a larger light on me anyway.
 
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