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 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.


-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


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

because the box will be used later.


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

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


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.



BY using some wire connect all cell in series connection

just check the overall voltage of battery pack

it should be around 12 volts .


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)


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


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


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)


connect the battery circuit to the laptop

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


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)


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!!!!

<p>I'm Giovanni from the Philippines and I have to say how easy it was laptop battery repairing simply is (based on the steps presented.) Way too easy in fact that I had my own share of attempts of repairing good batteries that had gone bad instead using roughly similar methods. Then I read a forum discussion in a Battery University website stating that particularly laptop batteries manufactured after 2006 were deemed &quot;smart&quot; batteries (mcu-controlled.) it simply meant that laptop motherboards and their batteries were then designed to have an ability to communicate wherein battery status and performance data be stored in those microcontroller units within the battery itself. After every manufacture of these mostly lithium-ion types of laptop batteries (normally-off meaning no current flowing on either negative or positive leads), the said batteries were then activated by a code ( a serial number perhaps) programmed into it's mcu. This mcu with all of the pertinent data in it will allow the conduction of current and/or voltage in any of the leads so long as the mcu is alive. It simply means then that when all the battery connections are to be severed, the mcu chip with all of it's data stored &quot;dies&quot; and therefore go back to it's normally-off state (in Windows, either you will get a &quot;no battery connected or a connected, not charging&quot; icon..) And as would another forum on lithium-ion batteries in another website would suggest, no way in hell will they ever give anyone the activation code of their mcu chip. Though I did have a few successes of my own but the method I am using is a bit trickier since it involves hot swapping the set of bad ones with that of a good set of batteries all at once. In order not to damage the circuitry or the mcu, both set of batteries (the bad set and the good set) have to be discharge into their most nominal states (about 3v or less for a pack of 6 cells in cells of good condition based on my own experimentations. At this stage I cannot yet post images since I had not yet perfected this technique but at least, the general idea is there. </p>
<p>thank you very much</p>
<p>Actually we can recondition battery like this - <a href="http://batteryrecover.com" rel="nofollow">HERE</a> is simpe way to do this</p>
And one more thing if your battery's circuit is dead then you have find the correct circuit replacement...<br>Unless the connection may not work..
<p>there is no battery plastic cover it is open type sytem. there are many model of 18650 cell like 18650 700mah/2200mah/2600mah which one will suitable</p>
2200 mAh are commonly used...<br>But if you have 2600mah then use it..<br>Don't use 700 mAh....
<p>thnks bro but i doubt if i use wrong mah then battery will explode during heavy usage ??</p>
No it won't <br>If your circuit it OK...<br>That is why there are temperature sensors.<br><br>. for safety...
<p>hey bro i have repair my laptop battery by replacing 18650 cell . i can acces my laptop through this but problem is. it is showing '' no battery is detected '' and not charging but i can access the laptop </p>
Just try to fully discharge your battery then connect your battery charger to laptop
<p>if won't start anymore ?</p>
Just give it a try..it may help
<p>thnks bro i will try it</p>
<p>Good idea, thanks ! :) I used <a href="http://ezbatteriesreconditioning.com" rel="nofollow">this guide</a> to recondition laptop battery</p>
hey bro i need help, i think my laptop battry is dead. i need to replace it but the problem is i cannt find any similar type of my battery. battery is 6 cell battery of 18650 without battery box, there is a lebel on one of them &quot; battery pack c14-s6-3s2p4400-0<br> rating 10.8v dc::4400ah/47.52wh . my question is which 18650 cell x 6 model will suitable for this. there is no detail writen on the cell about the mah and voltage<br>
You can use any 18650 model cell found in almost all the laptop batteries..<br><br>Actually there are 6 cell INSIDE each laptop Battery....<br>Just make sure you don't damage your battery plastic cover and circuit because as you said you could not find any correct match for your replacement.....<br><br>Just harvest 6 good cells from any dead batteries..<br>And replace it with yours...one
<p>Thank you :) Good instruction. Actually we can recondition all types of batteries</p><p><a href="http://bit.do/batteryreconditionnew" rel="nofollow">Battery reconditioning guide</a> - very cool way</p>
Hi there. It was a very complete and useful help that you made. Thank u for that. <br>Also i have a problem, after changing the battery cells with another used pack cells,laptop detects the battery and says it's charging, but for real, no charge is added. The percentage stays still. <br>I donno what to do. I checked the circuit board and it has no problem. Please help. Thanks in advance.
Very simple <br>Just buy couple of more dead batteries make sure this time you buy same model batteries to avoid confusion <br>Or <br>If the circuit is dead then you can use other circuit from the dead ones....<br>&amp;<br>If not, just use the correct cells in YOUR battery pack...(if the circuit is somehow detecting then this also will be solved).....
<p>Dear Waqqa </p><p>I read your feature &quot;how to repairing laptop batteries &quot; </p><p>I am using Compaq 420 notebook using battery cell PH06-Li-ion-10.8v-4300mAh </p><p>i have 4 batteries these all shows charging 100 % but showing red cross , as remove charger it shows red alert . It shows 1 Hr 10 minutes but decreasing and works without charger 30- 50 minutes only . I broken one it found that using SANYO magenta colour UR18650A R1112 6 cells . them 2 was showing low voltage but 4 is ok and shows 3.7 V . Can I replace these 4 cell in other bad battery pack or must purchase all 6 new cells to repair . Pl suggest .</p><p>What things must be follow when using laptop continues 7-8 hours so battery not spoil, because during 7-8 hours charger also connected to notebook.</p><p>Waiting for response.</p><p>Apreetam , Delhi , India</p><p>apreetam.kumar@gmail.com </p>
Brother voltage is not the criteria it is just rough estimate...<br>You need to check the capacity of each cell using professional charger like IMAX b6 or any other.....but <br>You can also check it by 2200 mAh power bank available easily for 100-150 .....<br>Then you can finally say the total capacity of cell in mAh..<br><br>The good to use for your laptop are above 1500 mAh ...<br>For for detail <br>Check out my channel on YouTube <br><br>https://www.youtube.com/waqaralamlive<br>&amp;<br>https://www.youtube.com/hobbytomake<br><br>
<p>I like it so much :)</p>
Thanks for the lovely comment
<p>I have change the dead laptop (Lenevo 3000 G410) battery with new 18650 but the battery is not detected by laptop, nothing happens when powering up the laptop. When I connect the charger, battery charging lights blink and goes off in five sceonds. I don't understant either ciruit board get locked. Please help and provide any availble solution for this. I don't want to through my new 6 x 18650 cell.</p>
<p>it is easy to understand whole thing in this note. &quot;'bro'&quot;...</p>
Thanks for this response...
if i add some Li-Po in circuit can it increase some capacity or rather damaging the circuit?
(Sorry for so late response)<br>Yes ,<br>If you connect it properly by soldering or spot welding.
Thanks bro...
I like it
Thanks for the comment
<p>not even one mention of how highly dangerous, explosive and flammable lithium-ion batteries can be. I expect natural selection maybe at work here!</p>
<p>&gt;&gt;JUST open your original laptop battery and throw the cells </p><p>&gt;&gt;because they are all useless &amp; keep the circuit</p><p>If these are lithium cells, DO NOT throw them away. They can be recycled and shouldn't be put into the trash. </p>
Some time a l.t battery is dead <br>Becoz,, of circuit is dead not the batteries.<br><br>But sometimes few cells are dead in a battery<br><br>I have opened many l.t batteries <br>My experience was 60:40 where 60 is good 40 is below 1000 mah (can be used for other projects)
<p>Circuits never die. It locks itself and sets itself &quot;Permanent Failure&quot; 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</p><p>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. </p><p>And last warnings ; the battery can die even when upgrading firmware of battery (especially lenovo / IBM batteries with custom firmware ).</p><p>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.</p><p>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)</p><p>Sorry for long post and bad english. These are all my information about SBS 1.0 and 1.1 compatible batteries. </p>
Thanks for the detailed commect..!!!
<p>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.</p>
<p>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. </p><p>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. </p>
<p>I was going to add the same thought!</p>
You have to carefully open the battery box <br>You may get the circuit damage .<br>Sometimes the cells are all good but the circuit is dead.<br>Just through below 500 mah capacity cell.
<p>So if I have this right, you take a good, but old L.T. battery apart, and put the individual batteries in the bad L.T. battery ? </p><p>If the LT batt. you're starting with is &quot;old&quot; the batteries in it aren't any better than the ones you have. Otherwise, the &quot;new&quot; batt. would be very good and valuable. Where do you get a &quot;good&quot; LT batt. free or cheap ? Why not just get a good used one that fits your LT ?</p><p>But wait, you can't find good used LT batteries...ANYWHERE !</p>
Thanks for the questions<br><br>No.1 you have to buy 2-4 old dead batteries and harvest all cells from them now you have to find the good ones <br>Just charge and discharge each cell with IMAX b6 and note down the capacity in mah .<br><br><br>No.2 if you don't have IMAX b6 charger don't panic<br>Just buy cheapest 2200 mah power bank then open it remove it's cell and put your harvested cell charge it with your phone charger until full then charge your phone using that power bank and note down how much times it is charging your phone then just multiply by your phones capacity you will get the capacity of each cell.use more than 1500 mah capacity cells in your repaired l.t battery.<br><br><br>No.3 buy new cells (but they are not cheap and also beware online fraud).<br><br>Thanks .<br>Let me know this helped you.
<p>Or even just get a bunch of cheap 2200mAh powerbanks and use their cells? Especially if e.g. they're part of a phone network giveaway or the like...</p>
<p>I live in an area with a lot of businesses, and a few large school districts. They're always recycling old laptops. While the entire battery might not be good, you can break them down and some of the 18650 cells are. We use individual cells for some flashlights we have that fit 1 cell perfectly into them. One of the guys claims to have tested and swapped some cells out into a laptop battery, to make ones that will still work. You can find them, it just depends on your area. I suppose if you live somewhere without much technology, it would be a issue.</p>
<p>Valkem: That's a good point actually ... I work somewhere that gets through several laptops a year, and am sometimes asked to help with carting things out from the junk room to the recycling van. Might take the batteries off from now on...</p>
<p>I&acute;m really thankful for your principal instructable, but I&acute;m as well<br>not getting the principal subjectivewise confusing way of your explanations... ?!? <br>I&acute;am not critisizing your efforts but I&acute;m not too stupid as well... *;O)<br><br>I never did what you are suggesting, I&acute;am not an electrician guy but have a <br>basic understanding of how things are working here, SO I assume there are potentially dead cells<br>in the LT-battery, which are going to be replaced. In my naiv way to look at the project<br>why don&acute;t one just buy new cells (18650 cells ?!?) and substitute them with the old ones...?!? Further more<br><br>- Why buying an old dead laptop battery (the exactly same type &quot;I&quot; have or just any LT-battery type ?!?)<br>from laptop repair shop?!? <br>Because it is cheaper to harvest potentially old but still enough voltaged working ones comparing<br>to totally new ones...?!?<br><br>- Every LT-battery hat 6 cells...?!?<br><br>- How to open them, because they seem to be almost welded. This in terms open it to obviously reuse them...<br>Probably not efectively explainable here...<br><br>- &quot;...generally 3.6 or above volt batteries are good below this voltage are the bad ones...&quot;<br>I am confused: Don&acute;t these cells have a voltage of ~ 1,2 volt (My LT-battery has a roundabout voltage<br>of 10,8 V, 4400 mAh, 47 Wh). Ok, writing these last lines I get the impression that you mean the WHOLE <br>LT-battery, defining the voltage, from where reparing is actually necessary...?!?<br><br>- &quot;... (don't break the parallel connection but cut the series connection) ...&quot; This means I can not change SINGLE<br>cells because the paralell connection has to be stayed fixed as you described...?!?</p>
<p>Let's see...<br><br>1) I expect the idea is that between your own &quot;dead&quot; battery and the cheapie scrap one from the repair shop, you should be able to recover enough individual working cells to make a full set for very little money, and the remaining ones should have about the same wear level. Generally when you have a multi-cell pack, it only takes one or two of them going bad (even just partially if it's two of them) to drop the pack's maximum attainable voltage below the level of what's usable by the device you're trying to power. So if you have a 6-cell pack, and another one from the repair shop, and you find each has 2 bad cells... you can build a working battery out of the remainder and still have two spare.</p><p>Personally I'd just open my pack, test the cells individually and buy a replacement or two, as they're like &pound;6 to &pound;10 each even when bought individually, but if you have a laptop you want to revive just for kickabout purposes and you can get the &quot;dead&quot; pack for less, then this might be the more cost effective way.</p><p>2) No, there are different numbers. Which is why you might hear a laptop described as having, e.g. a &quot;3-cell&quot; (netbook), &quot;6-cell&quot; (more normal midrange type) or &quot;9-cell&quot; (power user / gamer / desktop replacement) battery. The output voltage is the same, but each 3-cell series block is - in the larger packs - run in parallel with the others, giving a higher capacity and providing a more stable voltage.</p><p>Sometimes a pack may have a number of cells that isn't a multiple of 3, but they're fairly rare these days.</p><p>3) Difficult but not impossible. Usually they're clipped together, in a way that means opening them will break the clips unless you have some very specific tools. If you're not bothered about the warranty (almost certainly expired anyway...) then it won't really hurt to put it back together with a dab of superglue in each corner or a single layer of tape run around the seam. Opening it the first time will require quite a bit of levering and slipping thin-bladed tools into the seam and prising the lid open, however. Or you could just be a chimp and try cutting it off, maybe sawing (or dremeling) along the seam very very very very carefully so you don't short any leads or puncture the cells...</p><p>4) Nooooo... you need to pay more attention or do a bit of background reading for yourself before asking easily answered questions maybe. Lithium-ion cells are 3.7v each (nominal, when fully charged), as opposed to dry primary cells (1.5v), alkaline primary cells (1.6 to 1.7v), acid rechargeable cells (2.1 to 2.2v), NiCad (1.2v), NiMH (1.25v)... etc.</p><p>Bear in mind the difference between a &quot;cell&quot; (the minimum possible &quot;voltaic pile&quot; for a particular chemistry, what you usually have in the form of e.g. an AA or button, and is often erroneously called a &quot;battery&quot;), and an ACTUAL &quot;battery&quot; (an arrangement of cells in series and/or parallel to provide a more powerful / higher capacity power source), which is usually a more square or oblong affair. EG a laptop battery (multiple AA-esque 18650 cells), a car battery (usually 6x lead-acid cells), an old-style &quot;6v&quot; torch or motorcycle battery (4x dry/alkaline or 3x lead-acid), etc.</p><p>In the case of mobile phones, they originally used packs equivalent to 4x NiCad or NiMH (and in the case of my Motorola 3388, literally 4x AAs, which slimmed down to a flatter custom-made pack in the &quot;e&quot; version I bought... but with a bit of tape holding the back on, could still be powered by a quartet of NiCad AAs or even alkalines in a pinch), but as the internal circuitry was refined and system voltage dropped from nominal 5v to 3.3v, started using single-cell Lithium Ion instead. (The tolerances in such hardware are actually fairly generous, and fully charged nickel cells can actually reach voltages rather higher than nominal, giving even the NiCad packs a reasonable running time before even reaching 4.8v total, let alone going below 4.5v which is where you may start having supply issues; 3.7v vs 3.3v is pushing it a little, but it's not too difficult to just use a PWM + capacitor regulator these days and it gives a good amount of leeway down to 3.0v...)</p><p>Laptops, you'll find almost all packs are rated at between 10.8 and 11.4v, depending on how the manufacturer has interpreted the finer detail of the internal cell specs, whether the fully charged voltage is measured with zero load or full rated load, etc; technically it should be 11.1v nominal (as it's 3.7 x 3), but some are optimistic, some pessimistic... the actual internals are basically the same. Some of the old original EeePC netbooks have 2- or 4-cell packs, and a 7.4v voltage (even their chargers only deliver - a slightly oddball - 9.5v), but that didn't last long. Don't think I've seen any 14.8, 18.5 or higher, but those would be the voltages any higher cell count packs would vary around.</p><p>The more reliable-seeming ratings for individually available 18650s I've seen vary between 2100 and 3400mAh (those which go to 4000, 5000 etc tend to be from more questionable sources and suspiciously cheap...), so I would expect your laptop battery is a 6-cell model with either 6x 2200mAh 18650s arranged in two parallel series of three each, or slightly higher individual capacities with a more conservative total rating to account for any variation in the individual cells and the charging process (more or less resistance in the connecting wires, even), lowballing the expected average, as well as the nominal voltage, to give a total watt-hour count that might actually be more like 90% of what you may potentially get (heck, 10.8 x 4.4 is actually 47.52, so by rights they could have said 47.5Wh or even 48). No-one really cares THAT much about the exact figures anyway so long as the machine doesn't quit on them after a stupidly short time :)</p><p>5) No mate ... you really don't seem to have much of an understanding of electrical circuits, so it might be better to ask a friend to do the job for you.</p><p>Series is all the cells in a row, connected positive to negative, making a single line. More voltage, but the same amp-hour capacity.</p><p>Parallel is side-by-side, connected positive to positive, negative to negative, making multiple lines through that bit of the circuit. Same voltage, but more amp-hours.</p><p>Connecting three 18650s in series makes a sub-battery that's effectively the same as (in your case) a cell of 10.8 volts and 2200mAh. Each of these should be recognisable in the pack either as a line of 3 cells soldered like so:<br>-(1)+..-(2)+..-(3)+<br>...or at least three that are close together and clearly wired like that.</p><p>Those two sub-batteries are then wired together in parallel to make the full 10.8v, 4400mAh setup. They may be side by side, end to end (wired such that +ve goes to +ve and -ve to -ve, and +ve is prevented from shorting to -ve), or in some other arrangement with more obscure (but still possible to figure out) wiring.</p><p>Or in other words:</p><p>. . . -ve[sub-bat 1]+ve</p><p>-ve{ . . . . . . . . . . . . . . }+ve<br>. . . -ve[sub-bat 2]+ve</p><p>Which is the same as</p><p>/ -(1)+ -(2)+ -(3)+ \<br>\ -(i)+ -(ii)+ -(i i i)+ /</p><p>What you're being told to do is to cut the connections on the individual cells, chopping them out of their individual series (including severing their connection TO the parallel bus between the two series, if they're in the 1/i or 3/iii positions), WITHOUT harming the bus or its accessory circuitry (thermal sensors, switches, regulators, on-battery voltage meters, serial number code chips etc) which may be harmed by careless slicing. Even if you don't harm those, it's still an additional faff having to wire the parallel connection back together instead of just putting a small bleb of solder onto the new cell to secure it into the series, or even just wedging it in place and relying on straight metal contact and friction to hold it together...</p><p>...hopefully that's clear enough now? :)</p>
<p>...actually, quick correction - in the case of this instructable (and the example batteries), there are multiple parallel connections (each with a pair of batteries involved), and the series connection is instead between those three parallel pairs. I don't know whether one setup is better than the other, more popular, etc. I think it's probably a matter of personal taste and convenience in each situation. I've certainly seen the setup I describe before...</p><p>(As well as an old Nickel pack which was basically eight C-cells all in series, making 9.6v... heavy as hell but at least they were easy to replace, as there was nothing fancier than a plain thermal diode onboard, and I had plenty of NiCad C's left over from an old RC Car...!)</p><p>Or in other words:</p><p>--- -ve{ -1+ }+ve -- -ve{ -2+ }+ve -- -ve{ -3+ }+ve ---<br> . . . . .{ - i +} . . . . . . . .{ -i i+ } . . . . . . . .{ -iii+ }</p><p>It does make replacing them a bit more inconvenient because of not being able to separate the individual cells out from each pair, though - and it's more than likely that the actual point of failure is just one of the two cells. This is most likely because it'd be hella difficult to cut them off &quot;cleanly&quot;, and there might be additional components like load balancers buried within the bus straps - even though technically speaking you could make a replacement connection with a couple of regular spring terminals soldered together on a strip of PCB with a interconnection point on the other side, with the cells duct taped together and the board tensioned against them with a further strip of tape.</p><p>Still, if you pop open both packs and you find that only one of the pairs in your old one has gone bad (consider that if it's down to 2/3rds of its original voltage - not capacity! - then the whole pack will be maxing out around 9.8 to 10.2v, which is generally where laptops start to cut out...), and there's at least one good pair in the other pack, then you can just make a couple quick pairs of cuts, swap the two around, and solder the new pair back into the chain (being careful to only cut and re-solder the interconnects, as equidistant between the affected packs / terminals as possible)... and, boomf, done.</p><p>Don't even know really if you need to pre-charge the replacements. Depending on how fussy (or sophisticated) your charger is, it might be able to &quot;regenerate&quot; a pack that's otherwise gone &quot;too flat&quot;, or out-of-balance, using a particularly modulated charge current waveform. Kind of like how a good car battery charger can revive an otherwise dead battery that's not worn out but has merely been allowed to run down to an abnormally low voltage that a plain trickle charger might not be able to fix because of how unbalanced the individual cells are.</p>
<p>I had a dead laptop battery, over 10 years old, wouldn't charge or last 30 seconds. Took the 18650's out and series charged them at 4.2 Volts per cell. Guess what, they are as good as new, hold charge and when tested under load were close to 2000AH capacity. I've concluded that the laptops charger was faulty not the batteries. I'm guessing this happens often but people think it's the battery pack. </p>

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