Don't bother calling Nikon unless you bought it within 30 days. I bought two batteries with my camera but did not need the second one until I bought the grip. The one I wasn't using reads out with an age of 3. Nikon would not replace it and in fact says that batteries are not covered under warranty.
I have discharged mine a few times until power was switched to the battery in the body, thinking that a few recharging cycles from the point of being dead would reset them. So far there has been no joy. The battery performs fine though, so I guess it doesn't really matter.
Scott Chapin Powder Springs, GA, USA Nikonians Team Member