Can you set up in menu for the camera to "automatically" switch to 2nd battery (if needed), in whatever order, if camera is set on a tripod for a long video take unattended? In 5 days I have to use the GH3 as a static wide angle shot of 2 speakers in a 2 hour debate. Don't have a grip yet but can have one by then no problem. I will be on a tripod elsewhere with a shoulder rig shooting first one and then the other speaker as needed, and would not be able to "manually" switch between the Panny's 2 batteries if one runs out before the event is over. I would think of course this functionality is built into the camera's menu options but need to make sure before I plunk down $160-170, as that is why I would specifically be buying the grip.

Thanks much

Yes, it is automatic.
You can set which battery it uses first (I have it set to use the grip first as it's easier to change)

The other option would be to get the AC power supply with dummy battery.