Introduction: Renew Your Laptop Battery

Picture of Renew Your Laptop Battery

Change Your Laptop Battery cells instead of buying expensive new battery...


Ethan1976 (author)2017-01-22

If the battery is a 2100 mhA can i use new 18650 cells of 4000mhA? will not change the output?

yaly (author)Ethan19762017-02-08

It will only last longer, but make sure it has the same physical size, should be the same if both are 18650s.

Tyran Tesmer (author)2016-10-16

Hi I've replaced cells of my 8-10 year old Fujitsu laptop with cheep cells but only got the same lifespan (45min tops). After re-soldering the pack and even replacing the original set of cells the laptop now alternates between 99% charged and 0% capacity continuously every 3 seconds or so and shuts down immediately once the AC power is shut down.

Could I have damaged the battery circuit?

PsychoDrake (author)2013-01-17

If the battery is a 2100 mhA can i use new 18650 cells of 4000mhA? will not change the output?

It's a bit late, but for anyone else wondering, there are no (true) 4000 mAh cells yet. The highest at time of writing is 3500 mAh. Anything claiming higher is a total fake.

gnanmorder (author)PsychoDrake2013-08-05

As long as the voltage is the same as the old batteries, you'll be ok.

Thomas0568 (author)2016-03-10

Excellent! Giving this a shot right now! Just what I needed...thanks!

kodfarki made it! (author)2015-11-20

My Acer laptop was so strongly glued together. So I had to damage the case to disassemble it. If I can, I will try to reuse circuit for another project.

NisalP (author)2015-08-21

This is a waste of money and time. I replaced my toshiba battery with new cells but buttery itself doesn't identify new cells. The problem is there is a microchip in battery which has the details of the battery. To reset the battery you have to reset the values on EEPROM of battery too. If you can find a datasheet of the MCU you maybe able to reset it by grounding the RESET| pin. Be causes!!!. Otherwise you have to use be2works software and GPIO cable. But you will not find it for free on internet. Best option is to go for a duplicate battery on ebay and replace the cells with orginal s3 battery before using it.

SurajS8 (author)2015-07-27

SheikhM (author)2015-05-22

How can i define which kind of cell i need to replace my dead cell of my laptop battery? My product is "Dell Vostro 1540 6 Cell battery". 4400 mAh, 6 cell.

There is no mention of volt, mAh rate on the cell.

Also please tell me where from can I buy and collect these cells? My local store doesn't hav these.

glendalf81 (author)2012-09-11

nice job but would it be possible to use NiMH batteries, they seem to be able to withstand a high number of charges

morigen (author)glendalf812015-02-09

2 years is late for a reply but the answer to your question is "NO". Not unless you change the charging circuit to suit different kind batteries.

DanielE15 (author)morigen2015-05-05

the chemical makeup of the cells should matter less than the actual maximum discharge current (measured in Amps) that the cell can withstand. As a rule of thumb, the higher the rated Ampere of a rechargeable lithium cell, the longer it's lifespan (because it takes less damage on recharging than a cell which can withstand a lower current)

dvdspeler (author)2015-02-18

Hmm I did this with my t400 thinkpad, expected 10.8A with 9 cells

Unfortunately when I connected it, it blew up the charging board. I'm glad my laptop is OK!

any clue what happened? I used fully charged cells. Too much juice I'm guessing...

DanielE15 (author)dvdspeler2015-05-05

Some of the cells in the pack must have had different amperage and/or were nearing their lifespan. Happens a lot with cheap knockoff cells that are more-than-often repackaged dead cells from the recycle bin.

That's why the multimeter is a geek's best friend :I

chris2u (author)2015-04-14

8 Samsung batteries for $17, these days, would be Chinese "fakes"!...When the Chinese rate a cell at 5000mAh, it means 500mAh in real life.....So you could expect a capacity of about 1Ah all up..

Genuine Samsungs or Panasonics are at least $13 each..

So cheaper to buy a new battery..

Surprisingly Laptop batteries from China are quite good with reasonable capacity.

Probably worth buying a laptop battery to get some half decent cells for your torch .

So don't throw that old battery away..pull it apart and check the cells with a meter, you may find a pair of dead ones and the others are OK :)

DanielE15 (author)chris2u2015-05-05

Not if you get them shipped str8 from the factory off Alibaba.

High-end 3100mah 20Amp Efest batteries (which have an authentication code sticker on each cell that you can verify on their site) are 4 to 6 usd per cell at most (not including shipping tho)

But yea, gotta' be careful of obvious knockoffs like those laughably tagged 6000mah batteries you might come across.

DanielE15 (author)2015-05-05

Wow, didn't even have to connect the new battery pack in parallel to the chip before desoldering the old one?!

AND the chip shows 100% right off?!!




ericogalindo made it! (author)2015-03-08

Just tried this with my OEM compal CBL21 Notebook. After painfully rewiring and soldering all cells I was happy to see a postive 12.6 voltage showing on the terminals of the circuit board, so I assumed the circuit board wasn´t damaged during the process, but when I plugged the battery on my notebook, it didn´t even turn on. I put the power cable and the windows detected the battery connected, but it didn´t show the % and as soon as I disconnected the power cable the pc would shut off. I suspect either I damaged the circuit in some way or it has some sort of safety feature that disables the energy supplied to the pc for whatever reason, a waste of 3 hours of my life and 28 dollars, very unhappy.

waqasjamil (author)ericogalindo2015-03-11

Polarity of cells must be correct as the cells are lined up with mix polarity settings and the soldering should be perfect to cell's attached steel strip. check for it.

JewelA1 (author)2015-01-21

t is only dangerous if you don't know what you are doing. Laptop batteries can take A LOT before they actually become dangerous.. Shorting them out, or deliberately placing them in a fire or anywhere hot.

xman2 (author)2012-03-28

good job

AgeingHippy (author)2011-03-07

Nice one.

My laptop battery lasts about 3 min so I permanently need to be plugged in.

I might just try your approach.


ehu (author)AgeingHippy2011-07-15

How did you solder the batteries together? And to the circuit?
Isn't it too dangerous to heat some li-po batteries?

lafontas (author)2011-06-21

Battery cells from eBay - 18650 3000mAh RECHARGEABLE BATTERY CELL 3.7v Li-ion x8 @ $14.01 with free shipping.

BigD145 (author)2011-06-20

Some batteries will self destruct if you do this. I remember ThinkPad batteries requiring a 12V current at all times or the circuit would basically shut off and never work. The simple fix was to use a bundle of AA's and hook them up before desoldering the new cells.

pithiki (author)2011-04-30

My acer L300D laptop shows a red x on my battery. The batery is not all dead.
The laptop can run on the battery for 15min.If i replace the cells in it will it work or do i have a bad smart circuit?

zack247 (author)2011-04-15

i got a new laptop with a 20 minute battery, i just replaced the cells and i hope it works! note that some battery shells dont even have glue, my gateway battery just had snaps.

also note, that it is highly reccommended that you let the new battery fully charge (without using the laptop) and fully discharge once before you use it as per normal conditions, this helps prime the new cells for the laptop.

Shagwell73 (author)2011-04-05

Where oh where did you get your 18650's for $17 for a set of 8 pray tell???

waqasjamil (author)2011-04-02

My Laptop now works for more than 2 hrs when fully charged..but one problem is that the battery cannot be calibrated as the sock one, because each cell has a little variation in voltage..

isacco (author)2011-03-13

Thanks for this instructable
How much do the lithium-ion cells cost?

waqasjamil (author)isacco2011-04-02

its cost me 17 $ for eight cells..

rvalotta (author)2011-03-07

Fair warning... Most Lion batteries have a max charge rating. once it has been charged that many times it will stop accepting charges.

zack247 (author)2011-03-07

well my battery lasts about a hour or so but i need to take my laptop with me.
i hope i can find some lithium ion batteries in the stores nearby...

Scatmanbrandt (author)2011-03-07

I have a Clevo D900T with a 12 cell battery, I'm lucky if it lasts 12 seconds on battery power. I've tried opening it before but I might just cut it open like you did with this battery.

rimar2000 (author)2011-03-07

Good job, thanks for sharing!

NachoMahma (author)2011-03-07

. Good job

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