The high-capacity Nikon EN-EL4a Rechargeable Lithium-Ion Battery works for the Nikon D2H, D2Hs, D2X, D2Xs, D3 and D3X digital cameras.  It can also be combined with the optional BL-3 battery chamber to be used with the MB-D10 grip for the D300 & D700 cameras.   It features Lithium technology, which ensures maximum battery life and maximum power. It also features No Memory Effect so you can recharge partially drained batteries without reducing performance.