Difficulty

Moderate

Steps

5

Time Required

                          1 - 2 days            

Sections

1

  • Read guide note How to rebuild a laptop CMOS battery
  • 5 steps

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Introduction

IMPORTANT: DUE TO THE ASSOCIATED DANGER IF THINGS GO WRONG, THIS IS ONLY RECOMMENDED FOR OLDER NOTEBOOKS WHERE READY TO INSTALL REPLACEMENTS ARE UNCOMMON. If a pre-built replacement can be purchased, this is (generally) better, due to the fact there is little to no cost saving vs. rebuilding. It is also somewhat error-prone and can create the same issue as a dead battery if the tape fails.

Guide notes:

  • The cell does not need to be covered 100%. Due to the risk of an explosion, you MUST cover every visible area at least to the point it is “protected”. Liquid electrical tape is used to do this since it can be removed cleanly if something goes wrong and provides a better seal without the risks introduced by using heatsink and a butane flame.Laptop disassembly is not covered. Every laptop is different, so yours probably varies from the one this was pulled from. Check iFixit or the manufacturer’s website to see how to remove the dead cell. NOTE: SOME TOSHIBA LAPTOPS SOLDER THIS TO THE MOTHERBOARD.This guide ONLY applies to coin cell rebuilds. Do not use this guide for other batteries.When adding tape to the cell, be very careful not to create a direct short. To avoid this, place the tabs slightly higher than the factory and cut the tape sorter then you need, but still holding reliably.

What you need

Step 1

              Determine what battery you need               
  • Most laptops use a CR2032 or 2025 cell. The CR2016 cell is uncommon.
  • Take the battery apart and check out what cell you need. This may be difficult depending on the wrap used.

Most laptops use a CR2032 or 2025 cell. The CR2016 cell is uncommon.

Take the battery apart and check out what cell you need. This may be difficult depending on the wrap used.

1024

Step 2

              Disassemble the CMOS battery               
  • If you break the leads, a new battery will need to be purchased.
  • After purchasing a battery, disassemble the CMOS battery. Use caution not to heavily bend the tabs. Too much damage may make them unusable.
  • Break the tabs off of the old battery. Dispose of based on your local laws.

If you break the leads, a new battery will need to be purchased.

After purchasing a battery, disassemble the CMOS battery. Use caution not to heavily bend the tabs. Too much damage may make them unusable.

Break the tabs off of the old battery. Dispose of based on your local laws.

Step 3

              Verify polarity and tape the leads onto the new cell               
  • ONLY USE ENOUGH TAPE FOR A FIRM HOLD. Using too much may lead to a shorted cell!
  • BEFORE INSTALLING LEADS ON THE CELL, TEST THE CELL WITH A MULTIMETER TO CONFIRM THE POLARITY!
  • After the polarity has been matched, tape the positive lead to the new cell. To remove the risk of a failed rebuild, start on the + side and cut the tape to fit comfortably.

ONLY USE ENOUGH TAPE FOR A FIRM HOLD. Using too much may lead to a shorted cell!

BEFORE INSTALLING LEADS ON THE CELL, TEST THE CELL WITH A MULTIMETER TO CONFIRM THE POLARITY!

After the polarity has been matched, tape the positive lead to the new cell. To remove the risk of a failed rebuild, start on the + side and cut the tape to fit comfortably.

Step 4

              Apply tape to the negative terminal               
  • To place tape on the negative tab safely, try and keep the tape you cut as close as possible to the example image.
  • If possible, OFFSET the tape and terminal placement from the positive as much as possible.
  • After confirming there is no tape causing a short, add tape to the negative tab and tape down the negative terminal onto the new battery.

To place tape on the negative tab safely, try and keep the tape you cut as close as possible to the example image.

If possible, OFFSET the tape and terminal placement from the positive as much as possible.

After confirming there is no tape causing a short, add tape to the negative tab and tape down the negative terminal onto the new battery.

Step 5

              Apply liquid electrical tape               
  • Perfect coverage is not required. Focus on covering the major parts of the battery.
  • After verifying both leads are securely held onto the new cell, apply liquid electrical tape to the battery. 2-3 medium thickness coats are recommended.

Perfect coverage is not required. Focus on covering the major parts of the battery.

After verifying both leads are securely held onto the new cell, apply liquid electrical tape to the battery. 2-3 medium thickness coats are recommended.

After building the replacement cell, install it in the notebook. Verify the battery works by setting the BIOS, powering it off and then removing the battery/AC adapter. If the CMOS memory is retained, your battery works.

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