After using for months, the battery get weak and cant fully discharge. Also in this situation the laptop battery’s 76% even less in work.Now we need to Calibrate laptop battery. I found a note about recondition laptop battery from HP laptop battery manufacturers handbook. Surprisingly, it offered some really helpful laptop battery calibration and maintenance tips, which Id like to share with you:

Calibrating a Battery Pack

When to Calibrate laptop battery
Even if a battery pack is heavily used, it should not be necessary to calibrate it more than once a month. It is not necessary to calibrate a new laptop battery pack before first use. However, make sure that the battery pack is fully charged, especially if it is the only power source.

Calibrate Inspiron 1720 laptop battery pack under the following conditions:
? When the battery status display seems inaccurate.
? When you observe a significant change in normal batteryrun time.
? When the battery pack has not been used for one monthor more.

How to Calibrate laptop battery
To Calibrate laptop battery pack, you must fully charge, fully discharge, and then fully recharge the battery pack.

Charging the Battery Pack

Fully charge the Apple A1185 battery pack when the notebook is in use. To charge the battery pack:
1. Insert the battery pack into the notebook.
2. Connect the notebook to external power through an AC adapter. (The battery light turns on.)
The battery light turns off when the battery pack is fully charged.

Discharging the Battery Pack

Disabling Hibernation
To fully discharge the battery pack, disable Hibernation temporarily.
To disable Hibernation:
? Select the Power Meter icon on the taskbar or access Power Options > Hibernate, and clear the Enable Hibernate support check box.

Discharging the battery Pack
After the battery light turns off, which indicates that the battery pack is fully charged, begin discharging the latitude d520 battery pack.

To fully discharge the Sony battery pack:
1. Select the Power Meter icon on the taskbar, or select Start > Control Panel > Performance and Maintenance > Power Options > Power Schemes.
2. Write down the 3 settings in the Plugged In column and the settings in the Running on Batteries column, so you can reset them after calibration.
3. Select the drop-down lists and set all 6 options in both columns to Never.
4. Select the OK button.
5. Disconnect the notebook from the external power source, but do not turn off the notebook.
6. Run the notebook on battery power until the battery pack is fully discharged. The battery light begins to blink when the battery pack has discharged to a low-battery condition. When the battery pack is fully discharged, the power/Standby light turns off and the notebook shuts down.

Recharging the Battery Pack
1. Connect the notebook to external power and keep the notebook connected until the battery pack is fully recharged and the battery light turns off. ?You can use the notebook while the battery pack is recharging, but the battery pack will charge faster if the notebook is turned off.
2. Select the Power Meter icon on the taskbar or select Start > Control Panel > Performance and Maintenance > PowerOptions > Power Schemes.
3. Reenter the 3 settings you wrote down for the 3 options in the Plugged In column and for the 3 options in the Running on Batteries column.
4. Select the OK button.

Now you already Calibrate laptop battery

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You can calibrate your iBook, PowerBook, MacBook, MacBook Air, or MacBook Pro computer’s lithium ion battery for best performance.

The battery has an internal microprocessor that provides an estimate of the amount of energy in the battery as it charges and discharges. The a1175 battery needs to be recalibrated from time to time to keep the onscreen battery time and percent display accurate and to keep the battery operating at maximum?efficiency. You should perform this procedure when you first use your computer and then every few months after that. If you normally leave your Apple portable computer connected to AC? power and very rarely use it on battery power you may want to perform this process once a month. The website?www.apple.com/batteries?has more helpful information regarding batteries and offers an iCal calendar to remind you to calibrate your battery.?

Note: If you’re not sure which model of PowerBook you have, see PowerBook G4 Computers: How to Identify Different Models for assistance.

Products Affected

iBook, MacBook Pro, MacBook, PowerBook, MacBook Air

iBooks and PowerBook G4s other than the PowerBook G4 battery (15-inch Double-Layer SD)

1. Plug the power adapter in and fully charge your computer’s a1185 A1022 battery until the battery indicator lights turn off and the adapter plug light goes from amber to green, which indicates that the battery is fully charged.
2. Disconnect the power adapter and use your iBook or PowerBook. When your battery gets low, you will see the low battery warning dialog on the screen. Continue to use your computer until it goes to sleep. At that point the battery has been sufficiently drained for calibration.
3. Connect the power adapter and leave it connected until the battery is fully charged again.

You have to fully charge and then discharge your battery only once to calibrate it. After that, you can connect and disconnect the power adapter when the battery is at any charge level.

Tip: When the A1175 A1185 battery reaches empty , the computer is forced into sleep mode. The battery actually holds a reserve beyond empty , to maintain the computer in sleep for a period of time. Once the battery is truly exhausted, the computer is forced to shut down. At this point, any open files could be lost. Therefore, it is important that you find an electrical outlet and connect the adapter before the forced shutdown occurs.

PowerBook G4 (15-inch Double-Layer SD), MacBook (all models), Macbook Pro Series battery (all models), MacBook Pro (17-inch) (all models) and?MacBook Air

The battery calibration for the PowerBook G4 (15-inch Double-Layer SD) and any model of MacBook or MacBook Pro has been updated because of a new A1079 battery released with this computer. With these computers, follow these steps to calibrate your battery:

1. Plug in the power adapter and fully charge your PowerBook’s battery until the light ring or LED on the power adapter plug changes to green and the onscreen meter in the menu bar indicates that the battery is fully charged.
2. Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in.
3. Disconnect the power adapter while the computer still on and start running the computer off battery power. You may use your computer during this time. When your battery gets low, the low battery warning dialog appears on the screen.
4. At this point, save your work.? Continue to use your computer; when the PowerBook G4 battery gets very low, the computer will automatically go to sleep.
5. Turn off the computer or allow it to sleep for five hours or more.
6. Connect the power adapter and leave it connected until the battery is fully charged again.

Tip: When the battery reaches empty , the computer is forced into sleep mode. The A1079 battery actually keeps back a reserve beyond empty , to maintain the computer in sleep for a period of time. Once the battery is truly exhausted, the computer is forced to shut down. At this point, with the safe sleep function introduced in the PowerBook G4 (15-inch Double-Layer SD) computers, the computer’s memory contents have been saved to the hard drive. When power is restored, the computer returns itself to its pre-sleep state using the safe sleep image on the hard drive.

You can calibrate your iBook, PowerBook, MacBook, MacBook Air, or MacBook Pro computer’s lithium ion battery for best performance.

The Ibook G3 battery has an internal microprocessor that provides an estimate of the amount of energy in the battery as it charges and discharges. The battery needs to be recalibrated from time to time to keep the onscreen battery time and percent display accurate and to keep the battery operating at maximum?efficiency. You should perform this procedure when you first use your computer and then every few months after that. If you normally leave your Apple portable computer connected to AC?power and very rarely use it on battery power you may want to perform this process once a month. The website?www.apple.com/batteries?has more helpful information regarding batteries and offers an iCal calendar to remind you to calibrate your battery.?

Note If you’re not sure which model of PowerBook you have, see PowerBook G4 Computers: How to Identify Different Models for assistance.

Products Affected

iBook, MacBook Pro, MacBook, PowerBook, MacBook Air

iBooks and PowerBook G4s other than the PowerBook G4 (15-inch Double-Layer SD)

1. Plug the power adapter in and fully charge your computer’s apple laptop battery until the battery indicator lights turn off and the adapter plug light goes from amber to green, which indicates that the battery is fully charged.
2. Disconnect the power adapter and use your iBook or PowerBook. When your battery gets low, you will see the low battery warning dialog on the screen. Continue to use your computer until it goes to sleep. At that point the battery has been sufficiently drained for calibration.
3. Connect the power adapter and leave it connected until the battery is fully charged again.

You have to fully charge and then discharge your battery only once to calibrate it. After that, you can connect and disconnect the power adapter when the battery is at any charge level.

Tip: When the battery reaches empty , the computer is forced into sleep mode. The battery actually holds a reserve beyond empty , to maintain the computer in sleep for a period of time. Once the battery is truly exhausted, the computer is forced to shut down. At this point, any open files could be lost. Therefore, it is important that you find an electrical outlet and connect the adapter before the forced shutdown occurs.

PowerBook G4 (15-inch Double-Layer SD), MacBook (all models), MacBook Pro (all models), MacBook Pro (17-inch) (all models) and?MacBook Air

The apple laptop battery calibration for the PowerBook G4 (15-inch Double-Layer SD) and any model of MacBook or MacBook Pro has been updated because of a new battery released with this computer. With these computers, follow these steps to calibrate your battery:

1. Plug in the power adapter and fully charge your PowerBook’s battery until the light ring or LED on the power adapter plug changes to green and the onscreen meter in the menu bar indicates that the battery is fully charged.
2. Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in.
3. Disconnect the power adapter while the computer still on and start running the computer off battery power. You may use your computer during this time. When your battery gets low, the low battery warning dialog appears on the screen.
4. At this point, save your work.? Continue to use your computer; when the laptop battery gets very low, the computer will automatically go to sleep.
5. Turn off the computer or allow it to sleep for five hours or more.
6. Connect the power adapter and leave it connected until the battery is fully charged again.

Tip: When the battery reaches empty, the computer is forced into sleep mode. The Ibook G4 battery actually keeps back a reserve beyond empty , to maintain the computer in sleep for a period of time. Once the battery is truly exhausted, the computer is forced to shut down. At this point, with the safe sleep function introduced in the PowerBook G4 (15-inch Double-Layer SD) computers, the computer’s memory contents have been saved to the hard drive. When power is restored, the computer returns itself to its pre-sleep state using the safe sleep image on the hard drive.