How long do the batteries typically last on a continuous recording of video, highest bitrate at 1080p30?

I have not timed it but not long enough. You can get a battery grip and double it.

Enjoy
Kent

Kent, what time do you get, approx? one hour, four hours, 1/2 hour?

It would help if we knew what camera you are talking about.

I did a test with my Panasonic G6 & there was still juice left in the battery after it had filled a 32GB SD card with over 2.5 hours of video.

I am sorry. I forgot to say the GH3

Sorry Alex but shooting is stop and go with the camera on and not recording at times. I have two batteries, that is sufficient for a long day. Batteries aren't too expensive and are quickly changed. I mostly shoot nature and love the GH3.

Enjoy