When you're on the road without access to AC power, the Westcott L60-B/U60-B Battery Grip with NP-F Adapter is a valuable and ergonomic tool that just might save your shoot.
The grip requires two NP-F970, 750, or 550 batteries (sold separately) and will give you an extra two hours of runtime at 100% brightness, or up to 4.5 hours at 50% power. LED indicators help keep you informed about your power level. This handheld grip features a standard 5/8" female receiver for mounting on any industry-standard light stand, while the built-in retractable feet let you mount the grip to the L60-B to stand independently.