Runs out of juice (4)
I believe the answer is:
dies
'runs out of juice' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dies that I've seen before include "Passes from life" , "Ceases to be, cutters" , "Stops working" , "Berkshire racecourse" , "one day in ancient Rome" .)