A bit depleted, get a top-up at the station (5)
I believe the answer is:
depot
'the station' is the definition.
(depot is a kind of station)
'a bit depleted get a top-up' is the wordplay.
'a bit' says to take the initial letters (I've seen 'bit of' mean this).
'get a top' becomes 'tope' (I can't justify this - if you can you should believe this answer much more).
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
The first letter of 'depleted' is 'd'.
'tope' back-to-front is 'epot'.
'd'+'epot'='DEPOT'
'at' acts as a link.
Can you help me to learn more?
(Other definitions for depot that I've seen before include "Bus station or warehouse" , "Supply base" , "Storage base" , "storeroom" , "Military HQ" .)