Pick up / Drop some items?

Is there a way to pick up or drop only a specific amount of items?
For instance, if I have a stack of 2000 batteries, is there a way for me to only pick up 500? As it is, apparently I can only pick up the entire stack or nothing at all.

Yes. Just enter amount of items to drop and press the letter.

Like

a - battery (25000)

You enter: 500a

Use the advanced inventory (defaults to “/”) and select the tile that you want to gather the items, after that press “m” that’s the lower case m pressing M does nothing, after that you can select the specifc amount of goodies you want to grab.