The battery charger is pretty bugged, it will clip the base floor and get stuck. This one I grabbed from a delivery box and used "place" in the inventory. The place where it got stuck is unreachable from underneath the base due to invisible wall. I also experienced this earlier when a delivery box was autodestroyed and the battery charger got stuck in an unreachable position underneath the drone delivery pad.
*edited* to add that it emits a constant sound of physics jitter that never stops
