After much time digging thru menus I realized my experianced 10 second max video time was caused by my Toshiba 32GB  "HC C326" being too slow.

I picked up a couple 32 gig cards and haven't had a bit of trouble. Might be a little over kill
SanDisk Extreme PRO 32GB UHS-I/U3 Micro SDHC With 4K Ultra HD Ready-SDSDQXP-032G-G46A

• Read Up to 95MB/s ; Write Up to 90MB/s
• 4K Ultra HD and Full HD Video
• UHS Speed Class 3 (U3)
  

Supported SD Card Types:
SD/SDHC/SDXC Micro SD
Max capacity: 64 GB. Class 10 or UHS-1 rating required.

I'm using the Samsung Pro microSDXC for 4k video and have not had any issues with it

http://www.amazon.com/gp/product ... 0NKP1P8D469C7XX3SQ4

DJI-Victor.lai Posted at 2015-1-21 14:35
Supported SD Card Types:
SD/SDHC/SDXC Micro SD
Max capacity: 64 GB. Class 10 or UHS-1 rating require ...

you can use 128GB gig too, because its SDXC, technically you can use up to 2TB if NAND existed that would fit into a package that small.

I'm using the Samsung EVO 64Gb Micro SD without any problems at all:

http://www.amazon.com/Samsung-Cl ... ds=Samsung+EVO+64gb

I am using a 64 gb SanDisk micro sd but at least in 4K the video lags, freezes and some green screen. Any Ideas?