Since I've had this question myself for a bit, and I finally got an HC7 in hand, thought I'd let any other curious types know that the older FP series batteries CAN be physically modified to fit the HC5/7 (I have a Dremel and I'm not afraid to use it....), BUT the camera DOES NOT LIKE THEM, and won't work, meaning there is also an electronic lockout as well as a mechanical one.

The FH batteries work in the older cams, but the FP ones are not forward compatible.

SO, if you wanted to get the newest Sony, budget for genuine Sony FH series batteries for backups...

Guess I'll be selling all my FP series batteries... sigh.

DB>)