After many hours of usage a laptop battery loses its' discharge time - it doesn't last as long as when it was new. The reason for this is because the internal memory of the battery has shortened the original capacity. Thus it remembers a shorter capacity than the longer one. This is due to charging the battery when it has not fully discharged. Here is a tip to reset the memory.You will need the following items:
- 19 and 10 Volt DC lamps with leads.
- A multimeter to measure resistance and Voltage.
- Two thin gauge wires about 3 inches long (should be able to fit into battery terminals).
- Electrical tape.
Locate the positive and negative terminals with a Volt meter using the two thin gauge wires - there may be more than two terminals. You just need to find the positive and negative. The voltage should be around or lower than 19 Volts. If the Voltage is higher than 10 Volts, insert the 19 Volt lamp to the terminals. The lamp should light.
Secure the lamp's leads with electrical tape to the battery and wait until the lamp extinguishes or go dim. This may take several hours depending on the level of charge the battery has.Then insert the 10 Volt lamp and wait again until it extinguishes. If the battery read 10 Volts or lower when first measured, then start with the 10 Volt lamp instead of the 19 Volt.We want to fully drain the battery with the lamps.If no voltage measures from the terminals, chances are the battery is bad and cannot be revitalized. Measure resistence between different combinations of each terminal with the Ohm section of the multimeter. If you read a short or low resistence, then the battery is bad - do not attempt to charge it. It could damage the laptop's power adapter.When you are confident that the battery has fully discharged, it's now time to charge the battery. Connect to the laptop and wait until the battery fully charges while the power adapter is connected. Do not power the laptop while the battery is charging - wait until it fully charges by observing the charging indicator on the laptop.When the battery has fully charged, test it by using the laptop and make note of how long it operates until it warns of a low battery level. If the duration has improved, congratulations! You are done. If it doesn't, then perform the above process again.