HOW TO REPAIR LAPTOP BATTERY ?

HELLO MY FELLOW !

I AM WAQAR

here, i will show you how to repair your laptop battery for very cheap at home.

+WHY ?

The laptop batteries consists of lithium cell which are called 18650 cells

they are not eternal

they have life period of about 2 years

+WHEN TO REPAIR ?

when you see your laptop is charged fully but does not last even half an hour or less.

which means the cells inside the battery are dead.

Step 1: REQUIREMENTS

-1 old dead laptop battery from laptop repair shop

-1 your laptop battery (which you want to repair)

some wire & tools like wire cutter etc...

and also some electric tape

Step 2: OPEN THE OLD DEAD BATTERY

Use some tools to open the laptop battery without damaging the battery box

because the box will be used later.

Step 3: GET THE 6 CELLS OUT FROM OLD DEAD BATTERY

Take out the 6 cells which are in 2-2 parallel connection.

(don't break the parallel connection but cut the series connection)

Step 4: TAKE OUT YOUR MULTIMETER & CHECK THE VOLTAGE

THIS step is very important !

generally 3.6 or above volt batteries are good below this voltage are the bad ones

voltage test is just temporary solution for the capacity check of 18650 cells

i recommend to use imax b6 charger for capacity test.

JUST GET 6 GOOD (18650) LITHIUM CELLS OR BUY THEM FROM AMAZON OR EBAY

Step 5: NOW CONNECT CELLS IN SERIES CONNECTION

BY using some wire connect all cell in series connection

just check the overall voltage of battery pack

it should be around 12 volts .

Step 6: NOW OPEN YOUR ORIGINAL LAPTOP BATTERY

JUST open your original laptop battery and throw the cells because they are all useless & keep the circuit

(if you want to keep then check the capacity if some of them are good then keep them for future projects)

IMPORTANT:

don't damage the circuit or battery box while opening the battery .

Step 7: CONNECT THE CIRCUIT TO THE BATTERY PACK

NOW by using some wires connect the battery pack to the circuit

IMPORTANT:

you will see 4 wires coming out from the circuit in which the longest is negative.

the battery pack will also have 4 wires 1 is negative and 3 are positive (one to the end and two between the battery pack)

Step 8: CHECK BEFORE PACKING BATTERY

connect the battery circuit to the laptop

and press power button to see it's working or not

IMPORTANT:

if nothing happens after pressing power button

don't panic connect the charger to the laptop for 5 minutes then remove the charger.

(if again not working just contact me with your problem)

Step 9: SUCCESS! JUST PUT BATTERY AND CIRCUIT INSIDE THE BATTERY BOX

the final step to put battery pack and circuit in the battery box.

do it gently .

use some super glue or tape to fix the joint of battery box.

!!!!WE ARE DONE!!!!

Comments

[Viq]

What's wrong with my laptop? It keeps destroying batteries shortly after replacement. Hp 840 g3

[MahimaSandeepa]

I have a problem in the circuit. It even doesn't take the power to output wires.

[namtran1976]

Dear buddies,
I personally think the replacement of old cells by new ones following this instruction will not work in most cases. This guidance may be suitable for the very old laptop models only. From my understanding, the laptop bettery circuit contains an EPROM chip and this chip has several functions for the battery, of which counting the number of charging and discharging is one amongst other functions. When the battery is almost die, the EPROM also records the status of the cells (i.e. nearly die), and if the replacement of the old cells by the new ones without the re-flashing of the EPROM, the replacement should make no sense at all. Re-flshing of the EPROM in the battery circut is done by a speacial device with a specific software so that the EPROM recognizes the new cells as brand new and counts the charging & discharging as zero or something like that.

Best,
Greetings from Vietnam

[waltermens]

I have followed the steps correctly; the batteries have been recognized but not charging so think the EPROM chip is not recognizing the battery
can the eprom chip be reset
how do we do that

[Dayal]

You are the only person with correct answer , yes we need to reprogram the BMS.

[AlanJacob688]

Thanks for the comment

[pmcgillan]

Laptop batteries are frail. I tried an external battery source set to 10.8 volts, but laptop doesn't turn on. Is it the last 2 pins on each end for plus and minus? Do I need to connect other pins?

[EyalS3]

I salveged many batteries from old laptops , and the biggest problem is to open the battery pack without breaking it. Is made to brake when opened.
How do you do it?

[UncleEd]

>>JUST open your original laptop battery and throw the cells

>>because they are all useless & keep the circuit

If these are lithium cells, DO NOT throw them away. They can be recycled and shouldn't be put into the trash.

[HOBBY TO MAKE]

Some time a l.t battery is dead
Becoz,, of circuit is dead not the batteries.

But sometimes few cells are dead in a battery

I have opened many l.t batteries
My experience was 60:40 where 60 is good 40 is below 1000 mah (can be used for other projects)

[ugur23]

Circuits never die. It locks itself and sets itself "Permanent Failure" flag then blows the fuse when it dedected some issues,like when 1 cell died in battery. one died cell will make battery extremely unbalanced , it will heat pretty much then battery will lock itself

Same thing can happen when battery is over discharged. Or when you overload the battery. It will blow fuse , then battery will enter pf mode.

And last warnings ; the battery can die even when upgrading firmware of battery (especially lenovo / IBM batteries with custom firmware ).

If you have a Lenovo/IBM battery. Dont try this. It will OK to disconnect cells . but when you reconnect new cells , it will enter pf mode and blow the fuse when you triggered a power reset of circuit / smb controller.

And when you trying to recell a battery , first disconnect GND at end of the cells , when you builded all cells , connect GND last. Because removing gnd will immediately power down battery controller. If you disconnect cells randomly , battery will dedect imbalanced cells and it will enter the permanent failure mode.(And if you have a battery with a external eeprom (like bq2040/2060) backup eeprom first in case battery gets locked , just rewrite backup to battery then powercycle the circuit)

Sorry for long post and bad english. These are all my information about SBS 1.0 and 1.1 compatible batteries.

[Krispyn]

You best my friend, well explained thanks alot

[AlanJacob688]

This is a really helpful comment for everyone those looking to make this instructable.

[Soumya 12]

Help me please I am working with lenovo (ibm) laptop battery bms.

[HOBBY TO MAKE]

Thanks for the detailed commect..!!!

[Krispyn]

Tell more sir

[MarkP176]

Yeah, but at the price of buying a new set of six 18650s I may as well just get a full replacement battery from a discount supplier... Hardly any difference.

[XulescuN]

You can buy a good quality 6 pack under 10 bucks (I am from Europe and I have buy them at 1.2eur/pcs). Let me doubt you will find a replacement for this amount...

[UncleEd]

We agree 100% about the economics. The purpose of my message was to try to keep the lithium cells out of the trash. Depending on the source you read, they may be a hazardous material.

One thing that may be relevant is where you live. There are differences from country to county in laws about protecting the environment, resources for recycling things that we Americans can recycle, and the cost of some of these things that are cheap and easy to find where we are.

[thalian]

I was going to add the same thought!