Laptop batteries can be one of the most frustrating parts of an older laptop. They differ from other types of
batteries in that they provide a relatively short service life and are expensive to replace.
It must be remembered that most laptop batteries cannot be repaired if damaged. This is because of their complex construction. And even if it were to be repaired, one would need specific and expensive instruments to do so.
The battery has two parts, the chemical and the digital circuit. Chemical part can be restored with the risk of getting your files would be corrupted. It should be checked regularly for compatibility every time you use existing chargers. Batteries must also be kept alive with enough
supply of voltage during cell replacements. Disconnecting the
circuit, if only for a fraction of a second, can erase vital data and render the circuit unusable. To assure continued operation when changing the cells, connect a secondary voltage through a 100 Ohm resistor before disconnecting the cells. Always keep in mind to remove the secondary supply only after the circuit is fed with the needed operating voltage from the new cells.