What memory card are you using today that is stopping after 13 minutes?
What video resolution and framerate are you using?
Recording for 30 minutes or longer is a problem for all "photographic" camearas. Many countries (although the US isn't currently one of them) tariff imports of "photographic" cameras differently than "video" cameras. But all modern "photographic" cameras can record video these days. An agreement (political treaty) was reached that as long as the camera could not record video for 30 minutes or longer then it would be treated and tariff'd as a "photographic" camera and not as a "video" camera.
SO... all manufacturer have camera firmware that stops the video recording after 29 minutes 59 seconds... to stay short of the magic 30 minute mark.
It's not a technical limitation... it's a political limitation that the camera vendors were forced to comply with.
Next possibility... the FAT32 filesystem cannot allow any single file to exceed 4GB file size. This is an SDHC card standard limitation (all "SDHC" cards use the "FAT32" filesystem format).
You can get around this by using the "SDXC" card (these are cards that can allow for extremely large filesystems and extremely large filesizes). The "SDXC" standard uses the "exFAT" filesystem format. Mostlyl commonly these are cards that have storage capacity greater than 32GB (e.g. 64GB or 128GB cards, etc.)
You can also have buffer issues.
As your camera records, it starts to fill an internal memory buffer with the video frames... and simultaneously tries to save those video frames to the memory card. The "buffer" is just what it sounds like... you can think of it like your kitchen sink. As long as the sink can "drain" water at least as fast as the tap can "add" water, then there's no problem. But if you've got a fast tap... and a slow drain... you'll be ok for a few minutes... but once the water reaches the top of the sink, it's going to be a mess. You have to have a drain that's at least as fast as the tap.
So it is with memory cards. Different cards have different "write speed" performance. You neeed a card that can support a fast enough write speed. If your card's "write" speed is just slightly slower than the camera's "recording" speed, then the buffer will start filling just slightly faster than than it can be emtied (by "emptied" I am referring to the camera transfering the contents of the buffer to the memory card so that it can clear more space in the buffer) ... the buffer eventually becomes full and at that point the camera has to halt recording.
Tim Campbell
5D III, 5D IV, 60Da
