Protected batteries vs IMR - safety
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    Default Protected batteries vs IMR - safety

    Evening all. Say, I see so many folks now going to the IMR batteries because they deliver a high amount of instantaneous current, and it just worries me a bit.

    If a mod or atty/cartomizer ever shorts out while using an IMR battery, there is no protection, the battery will self destruct. Lighthound.com wrote me in answers to several of my questions, "A dead short with an IMR cell will release a tremendous amount of current + heat."

    For many of us who have been vaping with protected lithium-ion batteries all along, we're used to knowing that a dead short in our mod/switch/atty/carto/etc simply means nothing happens. We can fix the problem with the mod, and voila, the batteries aren't even destroyed from the short.

    I'm thinking that at minimum, shouldn't be be letting one another know about the extra care needed to ensure there is no short in a mod set-up before putting in an IMR battery and pressing that button?

    Dunno, is anyone else concerned? Maybe this is being discussed elsewhere already?
    Last edited by SteelJan; 01-04-2012 at 11:56 PM.

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    Thanks for bringing this up! I was under the impression that IMR batteries were implicitly safer than regular lithium ion and therefore didn't require protection. I guess I haven't seen it discussed thoroughly on ECF but I might have missed a thread. Based on your post it suggests they are not as safe as protected batteries - is that correct? Experienced advice is greatly appreciated!
    Vaping since April 3, 2011 8:30am


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    An IMR battery does indeed use safer chemistry in that nothing should happen if undervolted during discharge, or overvolted during charge. If it is overvolted or run down too far, it simply dies, it won't work anymore, can't charge it anymore, it's gone. But if it gets a dead short, it's going to violently self-destruct.

    Lithium Ion batteries have a more volatile chemistry, they will violently destruct if overvolted or overvolted. That's why we all agree on using lithium ion batteries ONLY if they have the protection circuitry, a protected lithium ion battery. This tiny protection circuit board prevents the battery not only from being undervolted or overvolted, but also from a dead short; you'll push the vape button and nothing happens, nada, zip.

    Everyone takes our own risks with the big batteries we vape. But at least we ought to know what those risks are, yeah?

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    I think that it depends on what you're planning to do to them. :-)

    Seriously- Because of their much higher C rating, IMR batteries are safer in a lot of scenarios. You can't draw too many amps very easily at all. This is the reason a lot of authorities consider them safer- a lot less likely to melt down.

    In a dead short, though, higher C rating means more current to deliver, in a shorter space of time. On the other hand, protected Li-Ion...well- the protection circuitry is small, not too sophisticated, easily dropped. It can, and sometimes does, fail. If you're using protected Li-ion batts, you need to think of them as "usually protected" rather than "protected." THen you'll be fine.


    Also, if you're not used to using unprotected batteries, you need to be careful (check voltages) to be sure that you aren't overcharging or overdischarging. You can damage them, which certainly shortens battery life and may be dangerous.

    Personally, I'd say that IMR probably are safer for vaping applications, BUT all high power batteries are potentially unsafe. Both protected Li-ion or IMR are safe enough for me, provided that you are careful and reasonably cautious.

    Best,
    Ande
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    I thought I'd dug through all of ecf to see if anyone else had discussed this, but must have missed this one. It shows pictures of an IMR 18650 mod failure...
    http://www.e-cigarette-forum.com/for...r-18650-a.html

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    So if I understand it a dead short could happen for example if I were to insert a screwdriver into a battery connector while firing. Does it happen in a moment or does it require this to be for a length of time? Sorry I have limited understanding of this stuff, but I want to assess the risk. Is there a most likely scenario for this to happen on an ecig?
    Vaping since April 3, 2011 8:30am


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    Something that happened to me that would have been catastrophic if I'd had an IMR battery in it. But I had a protected lithium-ion battery in it.

    I got a mod from one of the popular modders. It occasionally didn't fire, I'd press the button and nothing would happen. Finally, I took it apart and found there were two wires that the modder had skinned-back too far, occasionally touching, making a short circuit. I rewired the whole thing and all was well. If I'd had an IMR battery in there, with the drip tip in my mouth when the first short happened, well, howdy-bingo.

    I don't know how long it takes for a shorted IMR battery to self-destruct when shorted.

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    Quote Originally Posted by SteelJan View Post
    I thought I'd dug through all of ecf to see if anyone else had discussed this, but must have missed this one. It shows pictures of an IMR 18650 mod failure...
    http://www.e-cigarette-forum.com/for...r-18650-a.html
    I think if you look hard enough, you can find about Any Chemistry or Manufactures batteries that have failed.
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    Interesting video of a deliberate shorting of an AW IMR battery and a Panasonic high output li-ion:



    I''ve had a short of an unprotected IMR in a mod. In my case all that happened was the spring on the negative terminal heated rapidly and collapsed, breaking the circuit. No harm done (apart from a toasted spring!), and the battery was OK. In mods where there is no obvious "fuse" to fail, like a spring or something the battery will presumably heat up a lot more and that could be dangerous.
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    Quote Originally Posted by Papa Lazarou View Post
    Interesting video of a deliberate shorting of an AW IMR battery and a Panasonic high output li-ion:


    I''ve had a short of an unprotected IMR in a mod. In my case all that happened was the spring on the negative terminal heated rapidly and collapsed, breaking the circuit. No harm done (apart from a toasted spring!), and the battery was OK. In mods where there is no obvious "fuse" to fail, like a spring or something the battery will presumably heat up a lot more and that could be dangerous.
    Interesting how the T-Shirt printer now turned battery seller refers to the Panasonic as an IMR, which Panasonic does not make. These are the kind of disingenuous vendors who should be avoided.

    Kudos to you Papa for noting that it is in fact a Li-Ion (LiCO) cell.

    Back to the OP most large cells contain protection, in the top. The PTC, a current limiting Positive Temperature Coefficient device installed in the cell cap to limit external currents in the event of an external short to the cell.

    The video shows the PTC in action, but I guess it also shows what the OP is concerned about as the higher density AW true IMR did in fact seem like it could be more dangerous under those extreme conditions.
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