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Thread: How Do Most Lithium Ion Batteries Behave When They Are Approaching End Of Life?

  1. #31
    Flashaholic* Got Lumens?'s Avatar
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    Default Re: How Do Most Lithium Ion Batteries Behave When They Are Approaching End Of Life?

    Quote Originally Posted by MarioJP View Post
    One week later, this cell in question remains at 4.12v (end charge termination was a bit high when cell was charged) But one thing is clear, when together with the other cells.

    This is the only cell out of the 3 that has far less capacity and voltage jumps higher when charging and drops futher down when discharging than the rest of the cell group.

    At first, i thought this cell had more charge than the rest, so what i did is discharged them all down to 3.00v equally. Did a slow charge and fair enough, the voltage in this particular cell kind of jump a bit higher than the rest after 5 min or so.

    Sometimes it can be off by .10v from the other 3. So yes, one week later, cell remains at 4.12v while the other 3 remained at 4.15v

    So does not look like it is a short, but i think this cell is nearing end of service much sooner than the other 3 due to abnormally heating up during charging even at low currents.


    Just out of curiosity out of this thread, anymore ideas as to why this cell is giving out sooner than the rest? They were all used equally in a power bank.

    Luckily the cells are in parallel configuration, so that's good at least.

    Strange behaviour from li-ions lol.
    I upgraded to an Xtar VC4S charger.
    It can test and rate a cell. It can answer questions like capacity or ability to deliver current.
    It's best to have as near matching cells as possible in a multi-cell applications.
    If the cells were matching when You placed them all into service, most replacements won't match the (good)cells that are still in your multi-cell configuration.
    I would retire the other working cells to single cell applications and upgrade the multi-cell application(s) with new matching cells as needed.
    I can say Your attentiveness with the use of Li-lion cells is a good safety practice.

  2. #32
    Flashaholic*
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    Default Re: How Do Most Lithium Ion Batteries Behave When They Are Approaching End Of Life?

    Quote Originally Posted by MarioJP View Post
    Just out of curiosity out of this thread, anymore ideas as to why this cell is giving out sooner than the rest? They were all used equally in a power bank.
    Sometimes, it's just bad luck. We don't really know the quality of the cells we buy. Most grade A cells probably go to the major manufacturers of battery packs for tools, laptops, vacuums, etc. They're likely the most consistent quality.

    It's just a guess, but the cells that resellers get may be rated lower, and are less consistent in quality. That doesn't mean they're bad, but it's more likely you could get one that's a little weak.

    Remember, we're not supposed to use lithium-ion cells at all. None of the major manufacturers want resellers to sell them to the public.

  3. #33

    Default Re: How Do Most Lithium Ion Batteries Behave When They Are Approaching End Of Life?

    Quote Originally Posted by Got Lumens? View Post
    I upgraded to an Xtar VC4S charger.
    It can test and rate a cell. It can answer questions like capacity or ability to deliver current.
    It's best to have as near matching cells as possible in a multi-cell applications.
    If the cells were matching when You placed them all into service, most replacements won't match the (good)cells that are still in your multi-cell configuration.
    I would retire the other working cells to single cell applications and upgrade the multi-cell application(s) with new matching cells as needed.
    I can say Your attentiveness with the use of Li-lion cells is a good safety practice.
    I was going to get the Xtar Dragon, but the SkyRC MC3000 changed my my mind. The ability to update it's firmware is what convinced me.


    And yup, i am now using brand new cells plus i upgraded my power bank that now supports QC charging and uses 6 instead of 4 cells.

    I like the fact that this new power bank has a locking mechanism to keep the cover from sliding open and how the metal contacts are tucked away from being exposed unlike the old one.

    These are the brand new 18650GA, and the seller was liionwholesale. They threw in 3 battery cases plus a 18650 XML-T6 flashlight for free.

    I do notice a "B" marking on all 6 cells. So i am guessing it's an internal grouping letter?

    As for the old cells. They will be used for light duties such as now my single cell flashlight, and bluetooth radio.

    This will be my 2nd set of cells since introduction to cylindrical li-ion world. Before that, it was just eneloops, sure they were safe, but they just don't cut it these days anymore at least for what i use them for. AA power banks are a joke lol.

    And I hate devices with sealed-in batteries from x brand company as you are at their mercy should something goes wrong with that device lol.



    And lastly, Awesome seller if looking to buy new cells.

  4. #34

    Default Re: How Do Most Lithium Ion Batteries Behave When They Are Approaching End Of Life?

    Even perfectly identical cells will wear unevenly over time depending on the wiring layout and their position in the pack.

  5. #35
    Flashaholic* Got Lumens?'s Avatar
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    Default Re: How Do Most Lithium Ion Batteries Behave When They Are Approaching End Of Life?

    Quote Originally Posted by MarioJP View Post
    I do notice a "B" marking on all 6 cells. So i am guessing it's an internal grouping letter?

    As for the old cells. They will be used for light duties such as now my single cell flashlight, and bluetooth radio.
    I am guessing the "B" indicates the tier of acceptance. Where as most all "A" cells are marketed to pack builders.
    There is one question You can ask of the vendor, Are those cells 2 or 4 terminal cells? 4 terminal cells provide more consistent
    High Discharge voltage compatibilities.

  6. #36

    Default Re: How Do Most Lithium Ion Batteries Behave When They Are Approaching End Of Life?

    Quote Originally Posted by Got Lumens? View Post
    I am guessing the "B" indicates the tier of acceptance. Where as most all "A" cells are marketed to pack builders.
    There is one question You can ask of the vendor, Are those cells 2 or 4 terminal cells? 4 terminal cells provide more consistent
    High Discharge voltage compatibilities.
    Good to know. I'll def look into it. When they did arrived, they were almost empty around 3.5v right out of the package. The invoice does states that due to shipping regulations, the cells were shipped almost empty and to charge before first use.

    So the cells were discharged before it was shipped.

    So far they seem consistent during charging. Definitely at it's rated capacity (3000mAh+)





    Now as for the old green cells, they still hold quite of charge even after 4 years of use and they really last using them for my bluetooth speaker. Just dang.

    Although i may just recycle the abnormal cell and just be 3 instead of 4 cells in this group.


    Update: Decided to just recycle this cell that heats up abnormally. So this is how Li-ions behaves as they degrade and finally, EoL.


    But first: discharging the cell to what i like to call, recycle mode lol.
    Last edited by MarioJP; 08-30-2020 at 02:04 PM.

  7. #37
    Flashaholic* snakebite's Avatar
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    Default Re: How Do Most Lithium Ion Batteries Behave When They Are Approaching End Of Life?

    was the heater a red sanyo?
    https://secondlifestorage.com/showth...=sanyo+heaters
    Quote Originally Posted by MarioJP View Post
    Hey guys,

    I have to give thanks for this thread that made me realize that when it is time to replace the cells lol. I have one particular cell that starts to heat up even at 500mA charge rate.

    This cell has reached 45c temp and luckily the charger safety features kicked in as it was flashing red. This cell was quite hot.

    Any idea why this cell heats up like that? I noticed the heating up starts when the cell hits around 4 volts, not even close to hitting 4.1 yet.

    I finally ordered replacement cells which are 18650GA an upgrade from NCRB's i suppose. Not liking how this cell heats up and it is making me nervous lol.

    Any idea what's going on internally with this cell?

    Thanks.

  8. #38

    Default Re: How Do Most Lithium Ion Batteries Behave When They Are Approaching End Of Life?

    Quote Originally Posted by snakebite View Post
    Wow that thread pin pointed the exact issue i was having. Was because it was the green Panasonic cell or ncr18650B which is the above cell in the pic.

    As far as the GA or red one goes. No problems at all as they are still new. Not even on the tenth cycle yet.

    It was the B's that were having heating up issues. At that time, that cell starts heating up around 3.9v and voltage just doesn't climb anymore.

    Another pinpoint from that thread is i did exactly that. Let that cell rest for a few hours and then slow charge, and that's when the voltage climbed to 4.2v without generating much heat.

    And yes, like what that thread says, it is only hiding a future problem and would have to repeat this every time. Not worth the effort and better off recycling it in the end.

    But good to know that i am not the only one. Pinpoint accuracy wow.
    Last edited by MarioJP; 09-28-2020 at 05:41 PM.

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