This is never a good idea.

A ton of old batteries in one place. The batteries themselves are probably not a concern, but if something happens to the facility, then you have a ton of problems.

Security of the facility is a concern if someone can get in and walk out with an armful of laptops.

Laptops don’t scale from a stacking stand point. Sure, close the lids and line them up. Then you’ll have a lot of failures. Older laptops are intended to cool through the keyboard and top vents by the screen.