Canon LP-E6 Rechargeable Lithium-Ion Battery Pack (7.2V, 1800mAh)

The Canon LP-E6 Rechargeable Lithium-ion Battery Pack (7.2V), has a capacity of 1800mAh, making it possible to shoot up to 850 shots at normal temperatures on a single battery charge. The battery is also more compact and lightweight than previous battery models.
The LP-E6 battery also communicates with the EOS 5D Mark II and 7D digital cameras, so that you can always check the remaining capacity on the camera's power source info screen. In addition, a unique feature of the LP-E6 battery pack is that it has a microchip encoded with an 8-character serial number. So when the battery pack is installed in the camera, you can register it using a menu command. Then track the condition and power characteristics of up to 6 batteries in your camera to ensure you use your batteries evenly and identify batteries that are near the end of their useful lifespan.