The maximum depth depends on the materials, I use a PVC housing and an acrylic dome which should be good for 100m (I will run a pressure test before selling them). Then there is the length of the cable to worry about as 100m is probably the max if you want to view the output on the surface.
The camera can be controlled from the surface so the battery will depend on the amount of time you are recording, I am currently limited by the size of my CFast memory card as 128Gb lasts about an hour when recording 4K (305MB/s), I will have to invest in a 1Tb (£700).