Waiting for the animation to finish.

Probably some sort of authentication and status checks of the inserted batteries.

From the comments it seems like there are no fully charged batteries ready to go, and you will be taking some other mostly-charged ones.

It should be able to correctly time most charges, so that you are always getting the highest battery charge state available at that stop.

Most kiosks have 30+ batteries, so each has a while to recharge before being 'summoned' again.

I can imagine it takes a few hours to fully charge these batteries (and to keep them cool), so if it's frequently used there wouldn't be any full batteries and swapping them would be a waste.

I mean it can be scaled up so that one of these stations has hundreds of batteries, an active cooling system etc etc, so it's a fixable problem.

Sure, but making you wait 20 seconds isn't going to make a noticeable difference there.

If swapping the battery takes about as long as sitting at a red light, that doesn't seem like a major problem.

My guess would be getting the phone out and logging in to some app to order the next two batteries. With a bunch of animations and key presses. And ofcourse some "I agree" buttons.

sleep(randint(30, 100))