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Thread: Help ! Confusion about IMR 18650 Batteries?

  1. #1

    Default Help ! Confusion about IMR 18650 Batteries?

    I just bought 3 AW IMR 18650 Batteries and saw after payment they were Unprotected. I saw nothing on the site ("Lightbound") for any
    Protected IMR 18650 batteries. There weren't any.

    Can someone explain if there is such a thing (Protected IMR 18650 batteries) and if so should I not be using those? That is the usual advice for the "regular", non-IMR 18650 batteries after all.

    Second, do IMR 18650 batteries use a different charger than 18650 batteries do?

    Thanks.

  2. #2

    Default

    Charger should be same but dont use a cheap charger on IMR.

    Unprotected IMR are usefull when high discharge required - push it too far and they could catch fire.

    Do not overdischarge IMR below 3.0 V

    Protected cells more expensive and slightly bigger in length.

    AFAIK IMR is unprotected and a different Chemistry to protected Li-Ions.

    Use procted whenever possible unless you need the properties of IMR as above.

    Sent from my ViewPad7 using Tapatalk
    Last edited by mohanjude; 01-21-2012 at 04:57 AM.
    During the day when I don't need a torch ... RC is my hobby http://rc.runryder.com/helicopter/gallery/47842/Always on the lookout for McGizmo/Kuku Titanium torches with Trits..

  3. #3
    Flashaholic*
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    Default Re: Help ! Confusion about IMR 18650 Batteries?

    IMR is not sold with a protection PCB attached. IMR is considered a safer chemistry (Manganese) than LiCo (Cobalt), one of the Lithium-Ion family. Unfortunately for the safer chemistry, IMR cells have a noticeably lower capacity than Li-Ion cells. I use both types of cells. The IMR is primarily applied in the lights with the XML LED which are able to draw very high currents. ICR or Li-Ion cells are used in XPG lights.

    A quick search on CPF will provide some other opinions. Check this link out.

    edit: I agree with the above recommendation that only protected cells should be used in lights with a series connection. That is one reason why I have a very strong tendency to purchase lights using single cells.
    Last edited by moldyoldy; 01-21-2012 at 06:27 AM. Reason: cells in series

  4. #4
    Flashaholic*
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    Default Re: Help ! Confusion about IMR 18650 Batteries?

    I've never got a good answer. "Safer" is too ambiguous to me; "safer" could mean safer in power tools or some other application. If IMR can't be overcharged, can't be over discharged, and still has the same possibility of explosion, then they aren't "safer" for typical flashlight situations. And maybe they aren't protected because the device they are running in is protected.

    Hope someone can clear this up for me too.
    Wish: 1) Super low beacon; easy find flashlight. 2) Low voltage indicator, so not stranded without light. 3) Simple, one handed control ring mode changer (magnetic control ring). 4) Flood beam for walking/tasks. 5) Pocket carry. 6) LiFePO4.


  5. #5

    Default Re: Help ! Confusion about IMR 18650 Batteries?

    Lithium cells by their chemistry can be volatile if mishandled. They were not designed to be used by consumers per say. That is why they are not widely available in your local shop. These cells are used to build cell packs and offered to flashaholics and other hobby enthusiasts with a caveat. You will see this caveat on all 'For sale' threads on CPF.

    IMR cells have no protection circuit against over discharge or over charging. This characteristic can be exploited so that high amp drawing flashlights can be run briefly to show what they are capable. If left on a table with the flashlight on without supervision there is potential for fire or explosion. Therefore IMR are not safe to use in flashlights that have no built in protection or cheap chargers that do not monitor charging carefully.

    If you are charging one cell at a time a cheap charger can cope with this. But if you have IMR cells inside a battery pack and charge them in series you could potentially have mismatched cells with voltage differences.

    Power tools have protection circuits built into the battery packs and the chargers balance the individual cells and monitor their voltage during charging. I have repaired many battery packs that the charger has deemed faulty by beeping and flashing the faulty light by disassembling the pack and replacing the offending cell / cells.

    Quote Originally Posted by snakyjake View Post
    I've never got a good answer. "Safer" is too ambiguous to me; "safer" could mean safer in power tools or some other application. If IMR can't be overcharged, can't be over discharged, and still has the same possibility of explosion, then they aren't "safer" for typical flashlight situations. And maybe they aren't protected because the device they are running in is protected.

    Hope someone can clear this up for me too.
    During the day when I don't need a torch ... RC is my hobby http://rc.runryder.com/helicopter/gallery/47842/Always on the lookout for McGizmo/Kuku Titanium torches with Trits..

  6. #6
    Flashaholic* 45/70's Avatar
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    Default Re: Help ! Confusion about IMR 18650 Batteries?

    Quote Originally Posted by snakyjake View Post
    I've never got a good answer. "Safer" is too ambiguous to me
    Hello again Jake. We've been over this before in another thread. Let me try an analogy that might help explain the differences between safety levels of LiCo, LiMn, and LiFe Li-Ion cells.

    Let's say we want to drive a car for one mile down a road at high speed without having a tire blowout. This stretch of road is littered with broken glass bottles, boards with nails in them, scraps of sharp metal, as well as other road hazards, that cannot be avoided no matter how you steer the car down the road.

    Now lets say we have a choice as to what tires we can fit our car with. First we have the choice of racing tires intended for track use. These tires are specially formulated with soft rubber compounds which aid in making the tire more "sticky" so as to hold the road better. Additionally, these type tires have a fairly thin tread design, so as to save weight, and add to the cooling efficiency. For this analogy these tires compare to LiCo/ICR Li-Ion cells.

    Our second available choice of tires we can use to run this course are intended for normal use, such as may be found on the typical "family car". These tires have a compromise in tread formula which is a bit harder, allowing for better tread wear, but still retain a reasonable amount of traction. Additionally these tires have a thicker tread design, as weight is not as much of a concern for normal driving and performance. These tires we will parallel to the LiMn/IMR Li-Ion chemistry.

    Our last available choice of tire type for this treacherous one mile run down the road is a tire designed for off road use, typically installed on vehicles with 4WD. The rubber formulation used in these tires is harder, and tougher so as to withstand typical off road conditions, such as gravel roads, rock climbing, driving over small tree limbs etc. Tires in this category usually have a much thicker tread, often with a tread depth alone, of as much as one inch, or more. Also, weight is not a consideration with these type tires, as the benefit of adding strength to the design is much more important than saving weight with these type tires. We will equate these tires to LiFe/IFR Li-Ion cells.

    OK, we now have three choices as to which tire we can fit to our car to attempt the one mile run down this hazardous course. Considering the obstacles to be encountered, we know there is a reasonable chance that we will have a blowout, regardless of which tire we choose. That leaves us with trying to decide which tire type would be the "safer" bet to complete the one mile run without having a blowout.

    Perhaps this wasn't all that good an analogy. I mean Li-Ion cells and tires? Still, there are some parallels, but also some areas where no direct link can be made. As far as safety though, I think the analogy is adequate. LiCo cells cannot take as much abuse as the other two chemistries. LiMn are somewhere in the middle, and LiFe cells are the most resistant to abuse. They can all "blowout" though. As I said in the other thread, there really is no "safe" Li-Ion cell chemistry. Some are just "safer" than others.

    Dave

  7. #7
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    Default Re: Help ! Confusion about IMR 18650 Batteries?

    IMR can dump a whole lot of power to anything that wants it. you can haz amazing candlepower in small packages with IMR

    IMR are unprotected, that just means -they are safe if-: you also bother to monitor charge times, depletion, and long
    term storage and ability to hold a charge with a voltmeter.

    Safe ? there are two types of -safe-:

    1) safe to protect the general public from themselves ? you want protected, or primaries and no chargers
    2) safe for someone into lights and familiar with voltmeters and treating a battery kindly ? all battery types except cheap chinese knockoffs

  8. #8

    Default Re: Help ! Confusion about IMR 18650 Batteries?

    Quote Originally Posted by 127.0.0.1 View Post
    IMR can dump a whole lot of power to anything that wants it. you can haz amazing candlepower in small packages with IMR

    IMR are unprotected, that just means -they are safe if-: you also bother to monitor charge times, depletion, and long
    term storage and ability to hold a charge with a voltmeter.

    Safe ? there are two types of -safe-:

    1) safe to protect the general public from themselves ? you want protected, or primaries and no chargers
    2) safe for someone into lights and familiar with voltmeters and treating a battery kindly ? all battery types except cheap chinese knockoffs
    Well said.

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