The Nikon EN-EL 18c Rechargeable Battery has a capacity of 2500mAh, an output of 10.8V, and 27Wh. Also, the battery can charge within the MH-26a or MH-26aAK chargers, and it can be used as a replacement battery for the Nikon D5, D4S, and the D4.
Nikon: D5, D4S, and D4