I'm looking for a tutorial on how to recover 18650 cells from laptop battery packs. Like what should I do, and what should I not do, how to test them to see their condition.

The way I'm doing it now is break the battery case with a screwdriver and pliers, then take out the batteries and remove the wiring, then put them on a charger to see the voltage. If the charger doesn't show anything I assume the cell is dead, if it shows below 2.5V I throw it away and if it shows above 2.5V I charge it to 4.20V at 500 mA. Then I discharge it at 1000 mA and the charger shows me the amount of current discharged in mA. I assume that's the available capacity. If it has above 1800 mA I keep it and charge it again, otherwise I throw it away.

  • 3
    \$\begingroup\$ Seems to be a sensible approach. \$\endgroup\$
    – JimmyB
    May 28, 2017 at 12:35
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    \$\begingroup\$ While a lot of people on YouTube seem to have some success with similar methods it should be noted that there are kinds of damage to the cells that are invisible and manifest as catastrophic failures only in conditions that are at the border of the cells specified SOA \$\endgroup\$
    – PlasmaHH
    May 28, 2017 at 16:31
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    \$\begingroup\$ It's stupid I know - but I'd feel a lot better if you actually mentioned you were recycling those you couldn't use. If you aren't, maybe do that? Maybe? \$\endgroup\$
    – Nohbdy
    May 31, 2017 at 19:55
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    \$\begingroup\$ But what does recycling mean? \$\endgroup\$
    – thelolcat
    Jun 20, 2017 at 17:49
  • \$\begingroup\$ Recycling in this context is less about reconditioning or reusing batteries and more about keeping heavy metals and chemicals out of landfills and water. Please just dispose of them responsibly. \$\endgroup\$
    – JYelton
    Dec 30, 2019 at 22:03

1 Answer 1


This is more, or less a good approach. If you know what the cells are, then you can compare the capacity it is showing with what it was showing when it was new. The other thing you could do would be to test them under a load closer to their rated load and see how they perform; do they sag badly, do the get very hot?

Lastly, be careful, you could get some fire out of them.


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