Recovering 18650 Lithium Batteries With Only a Paperclip




Introduction: Recovering 18650 Lithium Batteries With Only a Paperclip

Many salvaged 18650 cells from used laptop batteries are unusable due to them not being able to take a charge as they are at 0v. But there is a way to recover them. These cells have had their protection fuse popped which disconnects the positive battery terminal. Usually the fuse triggers when the battery pack gets to hot which can be the case with some laptops. Once recovered the cells are usually just fine.
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Step 1: Finding the Cells

The cells that can be recovered should look like this:

1. The cell holds no voltage

2. There is no rust on the cells. (If you see rust that means the electrolyte has leaked out and the cell cannot be used. The green cells shown in the picture has dots of rust underneath it and means that it cannot be used.)

3. Smell the top of the cell. If there is a sweet smell that means the electrolyte has leaked and the cell cannot be used anymore.

4. The cell should have no visible defects.

5. There is no continuity between the positive terminal and the negative terminal.

Step 2: Separating the Cells

Separate the cells by peeling off the metal tabs.

As you can see the cell reads 48mv this means that the cell is at 0v.

Step 3: Fixing the Cells

  1. Bend a paperclip
  2. Push the paperclip into the top of the cell
  3. Carefully push the paperclip down. If a hiss is heard than the cell may not be usable anymore as the seal is broken.
  4. If you had done it right and no hiss is heard the cell should now be showing voltage.


The cell no longer has a working fuse so do not stress the cell too much

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    24 Discussions

    I've recovered a few cells this way myself. Though, using a small blunted point. (a well worn flat screwdriver.) .. as for the paperclip, I would round the end (even a tightly bent "U"), which is still small enough to fit through the vent on most 18650's.) just passed on your i'able to a recent one which uses the cell for a replacement cell phone battery.

    Please don't do this. I've witnessed to many batteries cascade from people accidentally shorting them, and too many fingers almost get blown off, in my time. When lithiums die, recycle them. New ones aren't expensive anyway.

    9 replies

    These wont supply that much amperage. Also it is hard to get it to short like this as there is a layer of protection

    That's not how lithium batteries work. They have a constant amperage (usually around 2A for Samsung type laptop batteries) and a pulse amperage which is usually around 5A which can be sustained for, on average, around 30-60 seconds or so. It all depends on the load you put on them. Throw a 2ohm resistor on them, and your fine, but drop that to .5, and you're drawing 8A where your battery will cascade. What you're doing, is shorting the "protection" circuit to revive the battery, and if if you mess up, (which is pretty easy to do), you could end up causing a dead short. In other words, there is no more protection when you do this. Do it wrong, just once, and you're holding a bomb.
    What I'm doing is resetting the CID

    Yes, I'm using cascade to refer to the thermal runaway;

    But you aren't "resetting" it. You're shorting it, and I'm referring specifically to the protection circuit, not the battery. However, the tolerances between the +- are small enough that you could end up shorting them while doing this.

    I know what I'm doing I have done it 100s of times without incident. There's a layer of plastic over the neg terminal and I'm going nowhere near the terminal

    Look at this image. Http:// I'm physically pushing the CID down. understand that these cells do not have a PCB protection circuit. There is no contact from positive to negitive. Even if there was 2 seconds won't Destroy such a low amperage cell

    There is no protection circuit on the cell. I'm pushing a mechanical device down in order to have it make contact with the cell itself. Now Google 18650 current intrupt device nothing is getting shorted.

    I don't get what you're saying. Yes I get ohms law but what do you mean by cascading? Do you mean thermal runaway? Because that won't happen with this unless the positive terminal gets shorted with the negitive and if the battery can supply enough amps. What I'm doing here is pushing a small circle of bimetallic metal back down to meet with the positive terminal, the negitive is not touched. Cut off the top of the cell with snips you'll see a concave disk, if it's a bad cell the disk will be convex pushing the disk together remates the CID with the positive terminal of the lithium. So I don't get how I am shorting the battery? Also there is no protection circuit on this cell as it's salvaged lithium.

    I really feel like you should know this stuff if you're posting this kind of info. Here's a good link to learn about battery protection;


    11 months ago

    it's look like a bit dangerous, no ?

    7 replies

    Since the paper clip isn't contacting the other terminal there isn't a chance of shorting. Also it won't contact the cell layers so it won't short. The only thing that gets touched is the CID and you can think of that like a can lid. It pops up due to heat and you can push it back down. The worst thing that can happen is a puncture of the seal which is unlikely.. If that where to happen small amounts of electrolyte leaks and drys the cell out not much else.

    Alex, I have one 18650 which reads .992 V. Iv'e been using it for vaping. My charger, a LUC S2, shows 0 V. and no luck charging. This doesn't look like the problem you describe. A throw-away?

    Not familiar w/the LUC charger? Google it (I know - you knew that.) .

    Thanks, Hugh Suggs

    If you are considering using this for vaping after 'fixing' it. Dont.
    Vapers stress their batteries.
    Just get new batteries

    I suppose it is fine 1v for a little while is not too bad

    Hi. The issue you are describing is that you have discharged your 18650 way too low that your charger will not accept it. There are many ways to fix this but I need to know what you have access to. Can you please tell me what brand of 18650 it is and how long it has been discharged? These will all effect the current capabilities of the cell. Generally good cells wouldn't really suffer while cheaper cells will. If you have a variable power supply you can Google: recovering 18650 cells by rinoa super genius. If you do not have a variable psu you can: buy an xtar v2(this is the easiest as the charger does it for you), buy a cheap 18650 power bank case from eBay and use that to charge it up. Or to parallel it with a aa batt and bring it up to 1.5 v then using a cr123 to bring it up to 3v. Use a 5 ohm resistor while doing so. Once at 3v it should be able to charge. There are many more methods of recovering cells just ask if you need to know.

    Thanks for your quick answer. I kind of thought that's what had happened. Thanks for the info, I belive I can save it now.

    Regards, Hugh

    Alex, sorry, I forgot you asked me for some info. It's a Panasonic, code IIEFH35, 05152666, on another spot it's marked with a B.


    11 months ago

    you should be very carfeful wiht this procedure. Usually, there's a reason why the CID was activated. You definitely need to apply further tests on cells that were reactivated (capacity, internal resistance) and if you use them, they need to be externally fused! I currently have 1680 salvaged 18650 cells in a productive powerwall and would never use reactivated cells like this... just an advice...