Taking extended videos (new user issues)

[Robmoo]

I was trying to video my daughter's play with the camera at the back of the room on a tripod.  The camera stopped taking video after 18 minutes.  I'm not sure why.  The battery indicator was still showing a full charge.  The 128gb memory card still had over 100gb free.  I had the camera in auto mode.  I videoed a 30 minute children's program with my youngest one with no isues.

I recently moved up from a 330HS digital Elph.  Any tips for this new user? 

[newsense52]

Camera is for taking photo not video, however it has option to choose for a short period of time, that's the design.

Stop the video when you think there is a break in the event you want to capture and not leave it alone.