Salvage Lithium Ion Batteries From Laptop Batteries




Introduction: Salvage Lithium Ion Batteries From Laptop Batteries

I'm a graduate of Aircraft Engineering Technology (Hons) in Mechanical. I am passionate about ene...

I am always curious to know what is inside any device. Recently I wanted to know about the type of battery inside a laptop’s battery after I have seen a video in YouTube, I believe it’s a video by kipkay about reviving an old laptop’s battery by replacing the lithium ion cells inside.

My good friend’s laptop battery was not working properly it was so bad that if his power cable is disturbed even a little the laptop would turn off immediately. The battery won’t even last for a second. He bought a new one and gave his old one for me so that I can satisfy my curiosity and maybe find some use for it. That was my first battery strip off and I didn’t take pictures of the full procedure and have added whatever I have taken in the last step named First Battery Strip Pictures, however I had another chance to open-up another friend’s laptop battery and have complete pictures of it (this ‘ibles will be showing the second battery strip, so let’s begin…

Step 1: Materials and Tools

Obtain the necessary materials and tools to get into the laptop’s battery


Laptop’s Battery any model will do (the bigger the laptop’s battery the more Li-ion cells in it)


Vise – to hold the battery

Rotary tool with mini saw blade attachment/ hacksaw/ plastic cutter (rotary tool is way faster obviously)

Flat screwdriver

Side Cutter

Long Nose/ Needle-nose Plier

Personal Protective Equipment:


Disclaimer: Li-ion batteries are dangerous and can catch fire if mishandled properly. Take necessary precautions when dealing with these types of batteries. Also follow safety precautions when using tool both power and hand operated to avoid injuries to yourself or others. I’m not responsible for your safety, be cautious of what you are doing and be safe.

Step 2: Opening the Case

First clamp the battery to a vise or use any tool available at your disposal to hold the battery in a secure position. Do not tighten the vise too much, just tight enough to hold the battery firmly.

I used a small vise, since that is what I have on hand.

I found that it is easier to cut along the line where the two halves of the plastic casing meets.

Ready your rotary tool with a saw blade attachment and cut only the plastic casing do not go deep as you will cut into the cell and it may cause fire (I haven’t cut into a cell yet). Go slowly and you should be fine.

If you are using plastic cutter, you may have to do it multiple times to cut through the plastic. (I have not tried it, however I did tried once with a scoring blade and I couldn’t get through maybe heating the blade and then cutting might have helped but then I got the rotary tool and things become easier).

After cutting along the joint, remove it from the vise and use a flat head screwdriver to pry the case apart. Insert the screwdriver and rotate it to get the plastic open. Be careful not to poke the Li-ion cells.

The cells will be glued to the plastic casing on one side using double sided tape, just pull the other side of the plastic apart and it should come off. Remove the cover and the guts of the laptop battery. You should be seeing Li-ion cells and the control circuit with temperature sensor (not sure of the type let me know if any of you do know).

Step 3: Removing the Cells

The cells are connected using metal tabs spot welded to them. I tested the battery voltage (10.23v) and it was close to the voltage of the working battery (10.8v).

First detach the temperature sensor from the cells by simple pulling away at the glued area. It should come off easily.

Note: If you are going to replace the cells and revive/ upgrade the battery make note of the connections made i.e., where the positives and negatives of the cells go and their orientation. I cannot promise that it will work as I am not sure why this battery was not working well. So if you do end up replacing the cells let me know how it went.

Then carefully cut the tabs/ wires that are connected to the circuit and between the cells using a side cutter.

Caution: Do not nick the cells, as it will render the cell useless.

You can leave the metal tabs for ease of soldering, should you require.

However I do not want sharp edges so I decided to remove the tabs.

Use a long nose plier and just roll away the tabs see pictures for more clarity.

Step 4: Usage and Charging Info

From my first battery strip-off, I have salvaged 6 cells of which 2 were dead and one was damaged during extraction. So I ended up having 3 in good condition. 2 temperature sensor and few smd components from the circuit board.

From the second battery strip-off, I have got 3 18650 cells and 2 temperature sensors and few other smd components from the circuit board once I desolder them.

The cells were not depleted completely, they were discharged but where within limits.

Use proper chargers to charge Li-ion cells.

Note: During my first attempt I accidentally nicked a battery while removing the tab from the battery using a wire stripper and it sizzled for couple of seconds with a little smoke. Checking the voltage later shown no degrade, therefore I assumed it is ok. When I used Li-ion Charger to charge this particular battery, it caused the chargers IC to burst and thus ending the chargers life. After which I never charged that particular battery.

Caution: Be careful while charging. Charge at your own risk. Do not charge the cells if it has been damaged. Expensive chargers might have protection to prevent them blowing up. However the cheap ones will just blow off the IC should the cell is damaged. Also watch the polarity when charging.

Currently I am using Nitecore i4 charger to charge the other cells and its been pretty good so far (for a completely dead battery).

I have been using the cells (from my First Battery Strip) to power my XML-U2 flashlight. And have plans to use it to power Arduino and also to make a solar power bank of sorts.

The later 2 are for future ‘ibles.

P.S: I have entered this 'ible in few contests, should it get accepted and if you liked it. Kindly vote so I could win something and make more and share...

Step 5: First Battery Strip Pictures

This HP battery was my first attempt to open a laptop battery unfortunately I didn't take pictures of all the steps. So I remembered to take pictures of the complete step the next time I open one.

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23 Discussions

I've just now salvaged 5 out of 6 cells from an old laptop battery and did the dremel cutting / cracking the plastic seam on the case approach. Once I'd got as far as being able to prise the case open with a screwdriver, it became apparent that the top side of the battery was actually a very thin plastic peel-able cover. If I'd known this when starting out, it would have been much easier getting the battery open by pushing a small screwdriver under the edge of this thin plastic top cover. It's probably worth checking for this first before attacking your battery with power tools

Hey! would it be possible to use these batteries as a portable laptop charger? i have an old battery, and i have a current laptop i would like to charge when in the car if needed, or when im not around a plug. Thank you!

2 replies

I am planning on doing exactly that with a few cells as a small side project. My laptop's fairly new and I like a lot about it but even brand new the battery life was awful so I feel your pain. All you need is at least three (preferably six) 18650 cells and this:

That thing is able to output 19V or 21V which both should be fine for charging most laptops. Just as long as it's on the right setting (whatever is closest to the voltage output of your normal charger) it should work fine. It also recharges the 18650 cells themselves if you give it a DC input of 16-24 volts, so you might be able to recharge it with your laptop charger too if you're lucky and it has the right barrel jack. Otherwise you can charge the cells separately.

I'm going to be assembling my own power bank using that very same device but I'll be used brand new 3400mAh 18650 cells so I can maximize the capacity. In theory it should work fine with salvaged cells though.

You could wire the batteries to a booster board that is set to your laptop's charger port voltage.

Hey there! I have a bit of a big project going on and after seeing this and several other instructibles I thought this would be a great way to get batteries for a battery pack to power it. I was hoping to make several 6S packs ultimately wired in a series parallel configuration to give 44.4V at whatever capacity I can get from the used batteries at hand. I went to a battery store and was given a bucket full of used laptop batteries for free, and I've managed to salvage over 75 individual 18650s. Only problem is, I now need to sort out those that are safe to use. Complicating the matter, I have several 3.6V cells mixed in with the 3.7V ones. Is there any reasonably efficient way to sort out the dead cells without needing to charge every one that isn't starting at under 2.5-3V?


I just salvaged 12 cells from old laptop batteries, but I have small issue with them. Six of then had 3.88V another had 4.08V, I get them charge thru one of that cheap 18650 charger to the 4.2V each, till that everything looks great but when I try found out their cappacity by discharging with LiPo charger at 1A I get only 480mah and at 0.5A 1200mah and Volts imidiatly falls from 4.2V to around 3.9V. I have pink one Sanyo cells, they should have 2600mah from 2010.

Can they lost so much capacity over the time??? Or I am doing something wrong??


I just salvaged 12 cells from old laptop batteries, but I have small issue with them. Six of then had 3.88V another had 4.08V, I get them charge thru one of that cheap 18650 charger to the 4.2V each, till that everything looks great but when I try found out their cappacity by discharging with LiPo charger at 1A I get only 480mah and at 0.5A 1200mah and Volts imidiatly falls from 4.2V to around 3.9V. I have pink one Sanyo cells, they should have 2600mah from 2010.

Can they lost so much capacity over the time??? Or I am doing something wrong??

hi,i would like to know on how to divide the two lithium batteries,because it is connected to each other by sum metal with negative symbol at the bottom and positive symbol at the would be a big help thanks

hey i have a doubt

im using the same lithium ion 18560 3.7 around 2000 - 3000 maH the thing is charging since i removed them out of the laptop battery i have a problem charging some could i charge these lithium of a 5v @ 1a charger or is there a problem

Noob here so please help

3 replies

hey there DIY_lover123

Unfortunately you shouldn't use 5V and 1amp charger for this battery, it will damage the cell and in the worst case it might catch fire. So only charge with the lithium charger designed to charge these.

If the cells are not charging, a person in another instructable commented saying to charge these non-charging ones by charging it with very less current of 0.1C and it may bring the battery back to life, if not recycle it properly. I personally haven't tried this, so not sure if it will work but worth the try.

In your case you will need to charge the battery with 4.2V and 200mAh - 300mAh.

i have searched the internet for a lithium charger all the chargers charge at 4.2v 1a and my battery is a 3.8v will there be any problems with it

For a battery to receive charge it has to be certain voltage higher than the battery's voltage and 4.2V is good for a 3.8v lithium battery.
Those chargers will have overcharging protection and sometimes short-circuit protection and will charge the lithium battery properly. So do use those and avoid using a wall wart to charge these batteries.

IN SHORT: Yup, those chargers are fine.

If the Voltage is down under 2.6V you can try to charge them with a low current until 3V are reached. Above 3V you can use the normal charging current Mostly this can bring your batterys back to life,

3 replies

Thanks for the tip, btw how to determine the low current value? Does it bring the battery's life back even after 5+ years of usage?

You have to try. to load them with 10%C, works for deep discharged 18650er. When the Batterys are very old, you can charge them this way but they do not have their full capacity anymore. I have recovered some 18650 that had only 1.7V .

It's just getting the voltage up. The cell will probably have one issue or another, so I'd only use those individually

i am trying to replace my battery cells.

i don't know how to check which cells are damaged.

any idea?

1 reply

This is the method I know and it worked for me so keep your options open for other methods as well.
Check each cell using a multimeter for its voltage, it should be about 2.75 (min) if it is then it should be good.

The next step is to charge it and see if the capacity is still there. For this you might have to remove the battery and then charge it using an external Li battery charger. Be careful while removing, making any dent or nick will actually make a good cell useless. And DONOT charge a nicked cell. I did with mine and below the cheap charger's IC. Use a constant current draw on the cell and determine the capacity, alternatively you could use a balance charger (the type used to charge and also discharge RC batteries) to check the capacity.
It is normal for cells to be at 80% or so capacity after few years of use.

Let me know if it worked out..

My son's and my Laptop / netbook batteries both died.. I will try to open them up and see what is inside.. thanks for the information

1 reply