One end of a battery (5)
I believe the answer is:
anode
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">one end of a battery</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for anode that I've seen before include "Eg, battery terminal" , "that comes out of a cell?" , "Negative terminal of a battery" , "Electrical terminal" , "A cell terminal" .)