12V Power points stay on.

Hi, I just bought a 2008 Laguna 3. I've noticed that the 12v power points stay if there is something plugged into them after I lock the car. For example, I have a dvd player hooked up in the back for the kids, but the indicator light for the charger stays on. Same for my phone charger in the power point in the armrest.

I havent been brave enough to leave it over night, as I cant risk a flat battery. Will they drain the battery, or will they eventually turn themselves off?

If they stay on, is there a way to change that?