The Nikon EN-EL4a is a rechargeable Li-ion battery providing 11.1v and 1900 mAh of power to select Nikon D-SLR cameras. The camera's fuel gauge accurately displays the remaining charge and number of shots since the last charging of the EN-EL4a. The EN-EL4a is charged using the MH-21 or MH-22 chargers. The EN-EL4a even gives notice when calibration is necessary.
The EN-EL4a is compatible with the following Nikon cameras: