Good quality laptop batteries can give a maximum 18-20 months of service depending on the usage. After that, you need to get a replacement battery for your laptop. However, you need to be very careful about the manufacturer and avoid buying the Chinese batteries which promise to a large capacity at low price. Samsung, LG, and Texas Instruments are world renowned manufacturers of battery components and take care of quality, safety, and lifespan of their components.
But, You can also renew your laptop battery by replacing the cells inside instead of buying a whole new battery. This is how you can do that.
Here is the HP laptop battery before the disassembly.
Split open the laptop battery with the help of the scalpel blade.
Carefully remove the scalpel to avoid damage to the internal circuitary of the battery.
Remove the battery casing carefully. You can see the circuit and the battery cells inside.
Replacing original batteries with 18650 Li-ion Samsung batteries. You can use any good quality battery from a reputable battery manufacturer.
First de-solder the battery cells from other components with the soldering iron. Place in the replacement batteries and re-solder the points. Now put papertape on all soldered areas to avoid short-circuit.
Now the battery pack is ready to be closed again in the casing.
After placing in the battery components, securely wrap a tape around the battery pack. You can also use joining solution for this purpose.
Now you have a brand new battery without spending money on the whole new battery.