Difficulty

Moderate

Steps

2

Time Required

                          50 minutes

Sections

1

  • Repairing Any laptop battery - Li-Ion cell replacement
  • 2 steps

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Introduction

Beware - This tuto is higly experimental, Li-Ion cell present fire / explosion / burn hazards this guide is for educationnal purpose only and should not be reproduced without safety measures. Remember to always wear apropriate PPE and work in appropiate environment.

What you need

Step 1

              Identifying dead cells
  • Caution: Lithium-ion batteries can catch fire or explode if they are damaged or short-circuited—especially when they are charged. Be extremely careful not to bend them or short-circuit them with your probes.
  • Battery pack works by putting individual cells in parallel / series. Each cell has a nominal voltage / capacity and they are put together to give the whole battery pack it’s global voltage / capacity.
  • Here we have a 3s2p battery pack. This means that you have 3 serial attached blocks of 2 parallel cells.
  • The lefmost block seems dead, the cells reads a steady 0 volts on my multimeter.
  • The 2 other block show ~3.6 V which means they are still alive, great !
  • I haven’t tested individual cells from the 2 working blocks for a good reason. This battery pack has been stored for several monthes, if only one cell in the block was dead, the other (good) one would have discharged in it until it also dies ( which is what must have happen in dead block )

Caution: Lithium-ion batteries can catch fire or explode if they are damaged or short-circuited—especially when they are charged. Be extremely careful not to bend them or short-circuit them with your probes.

Battery pack works by putting individual cells in parallel / series. Each cell has a nominal voltage / capacity and they are put together to give the whole battery pack it’s global voltage / capacity.

Here we have a 3s2p battery pack. This means that you have 3 serial attached blocks of 2 parallel cells.

The lefmost block seems dead, the cells reads a steady 0 volts on my multimeter.

The 2 other block show ~3.6 V which means they are still alive, great !

I haven’t tested individual cells from the 2 working blocks for a good reason. This battery pack has been stored for several monthes, if only one cell in the block was dead, the other (good) one would have discharged in it until it also dies ( which is what must have happen in dead block )

1024

Step 2

              Replacing the dead cells
  • Here I have 2 scrap 18650 cells form another dead battery pack. They are still charged but I have no fear has the battery electronics will balance the charge levels later.
  • After this step, reassemble the pack and everything should be fine.
  • Remember that this a dirty fix and you should consider the repaired battery pack as NOT SAFE

Here I have 2 scrap 18650 cells form another dead battery pack. They are still charged but I have no fear has the battery electronics will balance the charge levels later.

After this step, reassemble the pack and everything should be fine.

Remember that this a dirty fix and you should consider the repaired battery pack as NOT SAFE

Pour réassembler votre appareil, suivez les instructions dans l’ordre inverse.

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                                                                                      21 other people completed this guide.

Author

                                      with 5 other contributors 


                    Damien Leflon

Member since: 12/27/2015

607 Reputation

                                      1 Guide authored                  



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Red B - Dec 24, 2017

Reply

Salut, je pense changer toutes les cells dans ma batterie de laptop morte. J’ai actuellemt 6 x Samsung 26H. Est ce que je peux installer plus puissant ? Des LG HG2 18650 3.7v 3000mAh 20A High Drain Flat Top par exemple ? pour augmenter en duree et de vie de la batterie de mon laptop. Merci.

Delrue Dominique - Apr 24, 2020

Reply

Bonjour Red B

CC (courant constant), CV (tension constante) ou CC-CV (tension constante avec courant limité).

Le premier (CC) prendra un peu plus de temps pour charger votre batterie.

Le HG2 est également un millimètre plus grand que le 26H.

Ci-joint deux liens vers leurs fiches techniques.

http://grobotronics.com/images/companies…

https://www.18650batterystore.com/v/file…

le HG2 est légèrement plus robuste que le 26H.

Bonne chance;

Homer 82

dkorablev - Sep 10, 2021

Reply

What will be considered a clean fix?

dipalyconsultants - Dec 5, 2021

Reply

Sir, usually battery packs are hermetically sealed with glue, though it is not impossible to open the case. Still, it is time-consuming to separate the two plastic portions of the case. Kindly suggest how quickly I can open the battery pack and oblige. Often BMS is faulty kindly advise whether the BMS are interchangeable?

Best Regards

Dr P K Maitra BHILAI, INDIA dipalyconsultants@hotmail.com

Leandro - Dec 25, 2022

Hello.

I don’t have any experience yet, but I’ve found out that you can open the involucre that seals the battery with banana oil.