The Switronix Power & Lighting Kit for Sony NEX-FS100U Camcorder from B&H includes an additional, higher-capacity Lithium-ion battery for the FS100U that also powers the kit's GP-H56S on-camera LED light. The kit also includes a Switronix PB70C charger for the battery.
The Switronix PB70-S PowerBase 70 battery is a 14.8V model (70Wh, 4.8Ah) that can be mounted under the NEX-FS100U camera as a grip and also supplies power to the kit's 100W-equivalent, daylight-balanced LED light (which in reality draws only 16W).