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Dead Lithium Ion Batteries

Discussion in 'Power Electronics' started by ag273n, Mar 9, 2017.

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  1. ag273n

    ag273n

    74
    4
    Nov 24, 2016
    I was fiddling around some way to power my projects --- Lithium Ion 18650 Cells and found this YT channel - Rinoa Super Genius, he's building his own e-bike battery pack out of laptop batteries 18650 and he occasionally gets some dead Lithium Cells...
    He showed that Dead Cells can still be used - but just has some Special way to treat them given their poor condition. He started with a very small amp rating - like less than 200 mA and was able to get the battery up to 3+ volts..
    now i had this 500mA 18650 charger and some dead Lithium Ion 18650 cells that are below 2 volts. i put them on the charger and had it there for about 3-4 hrs, they're back to 3.3v!... max i was able to push in was 3.6volts!.. the voltage does drop like 0.001 in every 10 seconds on some cells, but i'm starting to think these cells seems still usable. the three laptop batteries i pulled these out from never got charged for maybe 2-3 years, but considering i spent no money at all for all the 16 cells i got- its a bargain!
     
  2. hevans1944

    hevans1944 Hop - AC8NS

    4,630
    2,159
    Jun 21, 2012
    Yeah, I'm with you, I never throw anything away that is presumed dead until I am dead sure it is dead and cannot be revived. I make two exceptions: (1) Alkaline dry cells that are "dead" will go in the trash if the cell voltage drops below one volt; (2) Nickel cadmium or NiCd cells I presume are made dead at the factory... any semblance of life from a factory-fresh NiCd is assumed to be an anomaly that will soon reveal its true character: dead. So NiCd are discarded immediately. Spent alkaline cells that might be useful for low-current bias or extremely small power demands are kept handy on the bench until they show signs of oozing battery blood, whereupon they head for the landfill.

    So good luck with your salvage project. Free is almost always better than paid-for unless your time is valuable.
     
    Merlin3189 likes this.
  3. ag273n

    ag273n

    74
    4
    Nov 24, 2016
    there were two cells i did take as seriously dead and dispose - those weren't taking any charge at all.

    i thought I'd put this info out since most people in forums I've read shunned using dead lithium cells... -and hardly any information how to use them. its that "special treatment" :)
     
  4. Audioguru

    Audioguru

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    Sep 24, 2016
    Lithium is extremely reactive and if charged or discharged wrong it can explode or catch on fire.
    A lithium-ion or Li-Po cell that has been discharged to below 3V is dangerous because the ions have converted to lithium metal that shorts the cells and causes an explosion or fire if it is charged with a normal current.
    A battery charger IC "tests" a lithium cell for a voltage too low then tries a very low charging current. If the voltage does not rise then it stops charging and sends an "error" warning.

    Your Lithium cell that does not hold a charge might become charged then at any time suddenly become shorted with lithium metal and explode.
     
  5. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,500
    2,840
    Jan 21, 2010
    NiCd's are great. Give me your old shorted NiCd batteries.

    They grow metallic whiskers which extend between the plates of the battery. At normal charge currents they simply conduct. The cure is to pass a brief high current through the battery. An electrolytic capacitor (maybe a few hundred uF) charged up to maybe 12V discharged across the affected battery is often enough to do the trick. NiCd can be left at 0V, so no additional damage accrues whilst they are shorted.

    NiCd batteries got a bad name more due to charging than the battery themselves.

    Having said that, I don't actually use them any more except in old equipment that has them installed.
     
    ag273n likes this.
  6. ag273n

    ag273n

    74
    4
    Nov 24, 2016
    on the past 72 hours, the batteries has stabled more. I closely observed them on a period of 7 hrs. the highest cell drop was at 0.003 volt.. Which was a big improvement from my initial observation - 0.001 volt per 10 seconds average.. I think the 0.001 volt per 10 secs drop was because i checked them right after the initial charge and was trying to be stable... when i started, none of these cells were at 3 volts, four of them were at 1.6 volts and the rest were somewhere around 2.4 volts.
    i have not subjected them on to any load yet.
     
  7. ag273n

    ag273n

    74
    4
    Nov 24, 2016
    i have never seen li-ion batteries catch fire in real life. -- maybe because the i've only come across cellphone batteries - which probably has protection circuits built into them. the ones i found in youtube catch fire were totally abused - like charged through a thousand volts and put into a lot of heat.
    the batteries i fear are the li-po's.. i've never used them, but there's so many media documentations and proof of them burning by ignorant users - of course when mishandled.

    my Ni-Cd's i use them for my camera. -- good batteries i can never fear :)
    given your statement steve. i'm growing more confidence on Ni-Cd's :)
     
  8. Audioguru

    Audioguru

    3,426
    738
    Sep 24, 2016
    A Li-Po is a Lithium-ion battery in a plastic case. A cell's voltage is 3.0V or 3.2V when dead to 4.2V when fully charged. Yours at 1.6V to 2.4V were discharged too low and are badly damaged.

    I last used Ni-Cad batteries about 20 or 30 years ago and every one of them ended up shorted. Ni-MH has replaced them. Ordinary Ni-Cads are not available here anymore because cadmium is a deadly poison that is available here only in Chinese jewellery and a few Chinese solar garden lights.
     
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