[FONT="]Laptop batteries rebuild
My Lenovo ThinkPad’s battery wasn’t lasting long due to normal wear. It was lasting about an hour with a lowest brightness and minimal use.
The battery back I got in my Lenovo is the original battery pack they shipped (from Singapore) with the laptop. Battery gauge reads 2008.05 as the firstly used month. However, after 5 years of use it became so weak and lasted about 2 hours (still not bad because of the 15.4 screen).
I wasn’t so happy with the runtime of that battery and decided to buy a one from a local store; their value was 9000/= for a used OEM battery (wow). It was too much for a laptop like this because I use this to download stuffs from the internet and for heavy use. Whatever people say about Lenovo, personally I know that Lenovo ThinkPad (original) is a very good laptop for hard users (I use this continuously for days and not heating up like HP or Dell, dropping down from my bed there is no care when traveling and just sitting on the car’s floor). Another reason to keep this laptop is it came with OEM Windows Vista Home Premium and I still have the product key sticker on the back plate.
Okay no more Lenovo marketing from me
this is how I rebuilt my laptop’s battery with 6 new cells witch are taken from a compatible battery and extended my battery life while it’s having the original casing.
[FONT="]This might be possible for all the laptop batte[FONT="][FONT="]ries[/FONT] whic[FONT="]h contai[FONT="]ns [FONT="]replaceable cells ([FONT="]I found some on eBay[/FONT]).[/FONT] [/FONT][/FONT] [/FONT][/FONT]
Disassembling battery packs
As I said, when it’s comes to Lenovo (original) they have a very nicely designed battery casing witch has used some clips to tight both top and bottom battery covers together. You have to open up this battery pack cover carefully without damaging plastic of it; you may use a flat screwdriver or a small knife for this.
Figures:[/FONT]
1. Opened up the old battery pack and revealed its cell positioning and design.
2. Disassembled compatible battery pack witch was ordered from China.
3. Carefully opened battery pack case.
4. 6 x 4v battery cells with the battery controller board.
5. Nicely and cleanly finished +12 terminals.
6. Cells after removing protective sticker.
Tip: When it comes to special places like mountings, it will have some glue to bond those plated together thoroughly.
Measure voltages of battery packs
Before I go ahead, I decided to measure voltages of those new and old cells and make sure that everything is okay and I’m not going to fry the controller board or my Laptop.
You’ll have to use a multimeter or a voltmeter and carefully touch positive and negative terminals with its probes without shorting out anything.
Figures:
1. Old battery’s voltage of a single cell (actually 2 cells witch are connected parallely).
2. Replacement battery’s voltage of a single cell (as above).
3. Old battery’s voltage of all 3 cells (actually 6 cells witch are connected parallely and in a series {2 by 2 parallely and each of them in as a series}).
4. Replacement battery’s voltage of all 3 cells (As above).
Tip: Be careful to not to short anything of those battery packs. It may damage your cells or fry your controller board!
Important: Some controller boards are designed to turn on battery protection or cut out battery output electronically if the battery voltage goes down after a specific voltage level. That means, if you de-solder the battery pack from the controller board (voltage is 0v) or short it out, your controller board might get tripped temporarily or permanently. So, you don’t need take that risk.
** As you can see, there is about 0.15v extra voltage when I measure the new cells. I didn’t worry too much about it
(Be careful to not to go over ~13v - ~14v or below ~10.8v)
Hint: If you have a tripped controller board, you can try to get that fixed by attaching a load (with a 10ohm – 100ohm resistor in a series) to your battery (to the battery output of the controller board +12v and 0v). If you have a tripped controller board, our attached load won’t work and you have to carefully connect a jumper (a wire) between +12v cell terminal and +12v controller board output.
Don’t do this for so long; just connect and disconnect if you have a good controller board and after removing the jumper wire, your load will be working continuously. (You may try GND or 0v output for some batteries like SAMSUNG).
Building up entire battery pack
Now, it’s time to build your new battery pack to match the original battery pack’s dimensions. Carefully exam the key portions of old and new battery packs and try to manage space of the battery cover to get fitted nicely.
Figures:
1. 9 cells of the compatible battery pack witch are connected so badly (original).
2. I’ve cut out 3 cells from the compatible battery pack to match the old pack.
3. Some terminals after cutting extra cells.
4. It’s how I prepared metal joints to solder.
5. Some finished joints.
6. I’ve placed the protective sheet (or may be a spacer) which is taken from the original battery pack.
Tip: Be careful to not to short anything when you solder or don’t heat them too much. Always focus the plastic protective sheet (blue) of the battery and don’t melt it.
Important: As I said above, if you really want to get your battery pack work after build, you have to focus on your controller board; attach a constant power supply (12v+, 8v, 4v and 0v) to the board temporarily (parallely) before disconnecting your battery pack from the controller board. Finally, solder the finished battery pack to the controller board parallely, cut off the temporarily attached source and de-solder.
Build terminals and connectors
This part is the hardest part of the rebuilding process. You’ll have to carefully map and build those metal wires to match the original design. Or you can use normal wires and do a crappy job too
Figures:
1. Original 0v wire.
2. 0v wire after rebuild.
3. Original +4v wire.
4. +4v wire after rebuild.
5. Original +8v wire.
6. +8v wire after rebuild.
7. Original +12v wire.
8. +12v wire after rebuild.
Tip: Be careful to not to short anything or heat too much and damage protective sheets. I used a 30w Japanese soldering iron for the entire process and 100w cheap quality soldering for the 12v terminal.
Re assembling
The last part of the re building process is the re assembling battery pack and attach it to the casing. If you have done a good job, it will fit nicely and properly.
Figures:
1. Protective sticker is bonded and cells are stuck tightly.
2. Spring used to operate the battery pack removal switch also properly attached.
Tip: Before you go ahead and attach the back cover of the battery, it’s a good idea to check voltage between two battery output terminals of the controller board. It should read ~10.8v - ~12.5v or if not, you may try jumper stuff or you have missed something.
Testing
Fortunately, I was able to power on my laptop with the re-celled battery pack I just finished and it’s lasts about 3.5 – 5hours with the maximum power saving power plan on Windows Vista. Battery is charging and discharging without any issues and the maximum temperature I detect is 40c.
Figures:
1. Lenovo power manager stats of the old battery I had.
2. Lenovo power manager stats after rebuilding the battery.
As you can see, it reports higher values after the rebuild process. Whatever this tool reports, I decided to go ahead and do a battery gauge reset and it took about 2hrs and 5mins to completely discharge the battery with the presentation mode on + full brightness + display on every time + continuously downloading windows updates with Wi-Fi. While this laptop has a 15.4” screen, 2hrs are okay with me and I will be able to use it up-to 3.5hrs – 5hrs with a good power plan.
Tip: Some battery stats such as cycle count, first use date or manufacturer won’t reset because those information are in the EEPROM.
:END:
Previous thread:
Save baby Squirrels - My experience
exit;
My Lenovo ThinkPad’s battery wasn’t lasting long due to normal wear. It was lasting about an hour with a lowest brightness and minimal use.
The battery back I got in my Lenovo is the original battery pack they shipped (from Singapore) with the laptop. Battery gauge reads 2008.05 as the firstly used month. However, after 5 years of use it became so weak and lasted about 2 hours (still not bad because of the 15.4 screen).
I wasn’t so happy with the runtime of that battery and decided to buy a one from a local store; their value was 9000/= for a used OEM battery (wow). It was too much for a laptop like this because I use this to download stuffs from the internet and for heavy use. Whatever people say about Lenovo, personally I know that Lenovo ThinkPad (original) is a very good laptop for hard users (I use this continuously for days and not heating up like HP or Dell, dropping down from my bed there is no care when traveling and just sitting on the car’s floor). Another reason to keep this laptop is it came with OEM Windows Vista Home Premium and I still have the product key sticker on the back plate.
Okay no more Lenovo marketing from me
this is how I rebuilt my laptop’s battery with 6 new cells witch are taken from a compatible battery and extended my battery life while it’s having the original casing.[FONT="]This might be possible for all the laptop batte[FONT="][FONT="]ries[/FONT] whic[FONT="]h contai[FONT="]ns [FONT="]replaceable cells ([FONT="]I found some on eBay[/FONT]).[/FONT] [/FONT][/FONT] [/FONT][/FONT]
Disassembling battery packs
As I said, when it’s comes to Lenovo (original) they have a very nicely designed battery casing witch has used some clips to tight both top and bottom battery covers together. You have to open up this battery pack cover carefully without damaging plastic of it; you may use a flat screwdriver or a small knife for this.
Figures:[/FONT]
1. Opened up the old battery pack and revealed its cell positioning and design.
2. Disassembled compatible battery pack witch was ordered from China.
3. Carefully opened battery pack case.
4. 6 x 4v battery cells with the battery controller board.
5. Nicely and cleanly finished +12 terminals.
6. Cells after removing protective sticker.
Tip: When it comes to special places like mountings, it will have some glue to bond those plated together thoroughly.
Measure voltages of battery packs
Before I go ahead, I decided to measure voltages of those new and old cells and make sure that everything is okay and I’m not going to fry the controller board or my Laptop.
You’ll have to use a multimeter or a voltmeter and carefully touch positive and negative terminals with its probes without shorting out anything.
Figures:
1. Old battery’s voltage of a single cell (actually 2 cells witch are connected parallely).
2. Replacement battery’s voltage of a single cell (as above).
3. Old battery’s voltage of all 3 cells (actually 6 cells witch are connected parallely and in a series {2 by 2 parallely and each of them in as a series}).
4. Replacement battery’s voltage of all 3 cells (As above).
Tip: Be careful to not to short anything of those battery packs. It may damage your cells or fry your controller board!
Important: Some controller boards are designed to turn on battery protection or cut out battery output electronically if the battery voltage goes down after a specific voltage level. That means, if you de-solder the battery pack from the controller board (voltage is 0v) or short it out, your controller board might get tripped temporarily or permanently. So, you don’t need take that risk.
** As you can see, there is about 0.15v extra voltage when I measure the new cells. I didn’t worry too much about it
(Be careful to not to go over ~13v - ~14v or below ~10.8v)Hint: If you have a tripped controller board, you can try to get that fixed by attaching a load (with a 10ohm – 100ohm resistor in a series) to your battery (to the battery output of the controller board +12v and 0v). If you have a tripped controller board, our attached load won’t work and you have to carefully connect a jumper (a wire) between +12v cell terminal and +12v controller board output.
Don’t do this for so long; just connect and disconnect if you have a good controller board and after removing the jumper wire, your load will be working continuously. (You may try GND or 0v output for some batteries like SAMSUNG).
Building up entire battery pack
Now, it’s time to build your new battery pack to match the original battery pack’s dimensions. Carefully exam the key portions of old and new battery packs and try to manage space of the battery cover to get fitted nicely.
Figures:
1. 9 cells of the compatible battery pack witch are connected so badly (original).
2. I’ve cut out 3 cells from the compatible battery pack to match the old pack.
3. Some terminals after cutting extra cells.
4. It’s how I prepared metal joints to solder.
5. Some finished joints.
6. I’ve placed the protective sheet (or may be a spacer) which is taken from the original battery pack.
Tip: Be careful to not to short anything when you solder or don’t heat them too much. Always focus the plastic protective sheet (blue) of the battery and don’t melt it.
Important: As I said above, if you really want to get your battery pack work after build, you have to focus on your controller board; attach a constant power supply (12v+, 8v, 4v and 0v) to the board temporarily (parallely) before disconnecting your battery pack from the controller board. Finally, solder the finished battery pack to the controller board parallely, cut off the temporarily attached source and de-solder.
Build terminals and connectors
This part is the hardest part of the rebuilding process. You’ll have to carefully map and build those metal wires to match the original design. Or you can use normal wires and do a crappy job too

Figures:
1. Original 0v wire.
2. 0v wire after rebuild.
3. Original +4v wire.
4. +4v wire after rebuild.
5. Original +8v wire.
6. +8v wire after rebuild.
7. Original +12v wire.
8. +12v wire after rebuild.
Tip: Be careful to not to short anything or heat too much and damage protective sheets. I used a 30w Japanese soldering iron for the entire process and 100w cheap quality soldering for the 12v terminal.
Re assembling
The last part of the re building process is the re assembling battery pack and attach it to the casing. If you have done a good job, it will fit nicely and properly.
Figures:
1. Protective sticker is bonded and cells are stuck tightly.
2. Spring used to operate the battery pack removal switch also properly attached.
Tip: Before you go ahead and attach the back cover of the battery, it’s a good idea to check voltage between two battery output terminals of the controller board. It should read ~10.8v - ~12.5v or if not, you may try jumper stuff or you have missed something.
Testing
Fortunately, I was able to power on my laptop with the re-celled battery pack I just finished and it’s lasts about 3.5 – 5hours with the maximum power saving power plan on Windows Vista. Battery is charging and discharging without any issues and the maximum temperature I detect is 40c.
Figures:
1. Lenovo power manager stats of the old battery I had.
2. Lenovo power manager stats after rebuilding the battery.
As you can see, it reports higher values after the rebuild process. Whatever this tool reports, I decided to go ahead and do a battery gauge reset and it took about 2hrs and 5mins to completely discharge the battery with the presentation mode on + full brightness + display on every time + continuously downloading windows updates with Wi-Fi. While this laptop has a 15.4” screen, 2hrs are okay with me and I will be able to use it up-to 3.5hrs – 5hrs with a good power plan.
Tip: Some battery stats such as cycle count, first use date or manufacturer won’t reset because those information are in the EEPROM.
An article from my own blog which is not posted yet. I own all the photos and all the materials I used here.
I’m not a computer repairman or an electronic specialist. I’m just a web developing guy who works as a freelancer. Everything is depends on your skills. So do it at your own risk as I did![]()
---------Mama native English speaker kenek newei. Eth English walin liwwe loke inna godak kattiyata meka wedagat wenna puluwan nisai. Anith eka mata meka sinhalen type aranna giya nam ada dawsama yai. Denatath peya 4k wage giya me okkoma hadanna. EK awith opadupa kiyawanawata wada wedagat wena deyak karanna hithuwa![]()
:END:
Previous thread:
Save baby Squirrels - My experience
exit;
Last edited:



kellek denmoth nam ho gala enawa 
unna hetiyata mala mokada kiyala man nam keduwa battery eka