I got out my old sony np fh100 battery that I got over five years ago for my Sony HC3. It is a huge battery, wasn't cheap.
I took a steak knife and trimmed the middle tags, it now fits the td 30 with almost 1" of battery sticking out. It has the same voltage as the battery that came the 30 ( 7.2v), 26.5 wh.
When I put it in the cam, under battery info it said it had 288 minutes and even then, that was with a battery that was charged over a month ago.
If you ever had a Hc3 hdv cam ( or maybe some other models) you might to dig out the batteries as they can work with the rd 29/30