Batteries only last 2 or 3 years at the most. If the auto diagnostics in you software suggest you get a new battery then you should trust the manufacturer to know its product. The deciding factor is the length of time that the computer will work on the existing battery. If it's sufficient for your intended use. Then you can delay buying a new battery. Cheap after market batteries can be a waste of money and can even be dangerous. I would only buy the manufacturer's replacement battery from a trusted retailer.