That seems too good to be true. Is that a manufacturer warranty?

Where do I find details on the battery warranty?
All batteries go bad after a while. Who will replace the battery when it start loosing charge in 3-4 years?
Does the battery warranty cover manufacturer's defects only? (In this case- it is no different from any other drills).
What kind of battery is included(NiCad, Lithium, NiMH)?
What are the Amp- hours?