system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can't a battery be charged instantly?
gpt
Several reasons.  

1.  The pipe that fills it would have to be huge.  

2.  The chemistry of the battery takes time to go from a discharged to charged state (you're literally re-arranging molecules).

Along #1, imagine a car battery typically ~50Ah @ 12V.  To charge it instantly you need to feed 50Ah worth of current into it in an instant [say a second].  So that's 3600*50A => 180000A of current.    Cable thick enough to handle that would likely cost >$1000 per foot.