A common alternative to buying a replacement battery is to rebuild a battery. Basically, it involves replacing the cells inside your original battery and replacing them with new ones that can be purchased online. The process can dangerous, as any mistake can easily set your laptop on fire, not to mention risk your home or office.
Aside from the risks involved, the process may not necessarily return your battery to its original capacity, as this DIY laptop battery rebuild guide reveals. Always consider an OEM replacement, or a refurb done by pros before attempting a battery rebuild.