Is the 7 pin connector hot when engine is off?

[Lederman]

When the T4R engine is off but still plugged into the trailer is the trailer battery pulling from the T4R battery? Or is the 7 pin connector only hot when the vehicle is running? If I camp overnight and leave the 7 pin connector connected and the battery in the trailer runs down will the trailer deplete the truck battery?

I am urban dry-camping so I would like to not plug and unplug the trailer if I can avoid it.

Thank you for your thoughtful advice.