The Nikon Standard for “shots per charge” battery information for its cameras is based on testing done by Nikon Inc.
Example: A Nikon D3 equipped with an AF-S VR 70–200mm f/2.8 ED lens captured 4,700 images when measured at 20 °C/68 °F under the following test conditions: image quality set to JPEG normal; image size set to L (large); shutter speed 1/250 sec.; shutter-release button pressed halfway for three seconds and focus cycled from infinity to minimum range three times; six shots taken in succession with the monitor turned on for five seconds and then turned off; cycle repeated once exposure meters have turned off.
Real life results will vary depending on factors such as temperature, use conditions and the number of times the battery is recharged.