I bought this battery because I do a lot of filming at sporting events and needed something that would last for several hours at a time without having to worry about changing batteries at a critical moment. Fully charged, my battery gives a nominal eight (!) hours of use but in reality, when I film (with a lot of zooming in and out) a realistic time is nearer to five hours. Cold weather is the enemy of all batteries but this one has held up very well in terms of retaining charge in low temperatures.
In terms of performance, I can't fault this battery at all but from a practical point of view, I'd advise any casual video photographer to avoid buying it. The battery is quite large and heavy and if using it with the latest generation of Sony HD camcorders, it will make the camera feel unbalanced in the hand. I use this battery when my camera is attached to a tripod so for me, this isn't an issue.
I'd suggest that anyone looking for extra "oomph" to supplement the tiny battery that comes as standard with a Sony camcorder should go for the FV-70, which is a much nicer size when using the camcorder in handheld mode (and provides more than enough shooting time for a casual photographer). If you're looking for a workhorse to use for extended periods of filming, this is the battery for you!
