The Sony FZ-100 battery is definitely a step in the right direction compared to its predecessor, but it still can leave a little to be desired if you need to power your camera for long shooting days on location.
That's where this simple beauty comes in. It coverts a p-tap (or d-tap, depending on where you're from) into a "dummy" battery that fits in the usual FZ-100 battery slot. It converts a 10-18 Volt signal into a safely regulated 8 Volts so it won't fry your camera.
The relaxed cable is about 16" long and the coils extend to roughly 30" when fully straightened.