Nikon
EN-EL18b Rechargeable Li-ion Battery
For D4, D4s, D5 & D6
Designed to power your D4, D4s, D5 and D6 DSLR camera, the EN-EL18b Rechargeable Lithium-Ion Battery from Nikon provides 10.8V of output power, a 27Wh rating, and a capacity of 2500mAh. It is available here as a spare or replacement for the battery supplied with your camera.
It can be charged using either the MH-26a Battery Charger supplied with the D5 and D4S or the MH-26 Battery Charger supplied with the D4. The battery requires the BL-6 Battery Chamber Cover, which is available separately and included with the D6, D5 and D4S.