Posted a thought about this on your youtube video. 
I have no direct experience with those Tesla packs, but..I have a hard time believing that they would build anything that would allow water to get into the pack but I need to make sure.
Thanks!
Good idea. I should be able to easily send 12 v to the pump to see what happens. I imagine that it would blow air out but Ill see.Maybe they are maintaining a positive air pressure in the pack? Would be useful to apply 12V to that pump and see what happens? Is the external air sucked in through the dehumidifier beads?
The Model S/X packs are not strictly 'airtight' because they have the exhaust valves along both sides. They also don't have any dehumidifier beads. The only feature they do have is a pressure equalisation valve.