Battery
Middle English: from Old French baterie, from battre ‘to strike’, from Latin battuere . The original sense was ‘metal articles wrought by hammering’, later ‘a number of pieces of artillery used together’, whence ‘a number of Leyden jars connected up so as to discharge simultaneously’ (mid 18th century), giving rise to battery (sense 1).
wiktionary
Borrowed from Middle French batterie, from Old French baterie(“action of beating”), from batre(“battre”), from Latin battuō(“beat”), from Gaulish. Doublet of batterie.
etymonline
battery (n.)
1530s, "action of battering," in law, "the unlawful beating of another," from French batterie, from Old French baterie "beating, thrashing, assault" (12c.), from batre "to beat," from Latin battuere (see batter (v.)).
Meaning shifted in French from "bombardment" ("heavy blows" upon city walls or fortresses) to "unit of artillery" (a sense recorded in English from 1550s). Extension to "electrical cell" (1748, first used by Ben Franklin) is perhaps from the artillery sense via notion of "discharges" of electricity. In Middle English, bateri meant only "forged metal ware." In obsolete baseball jargon battery was the word for "pitcher and catcher" considered as a unit (1867, originally only the pitcher).
