The story
Partial calque of German Battenberg (literally “Batten mountain”), equivalent to mount + Batten. The name was anglicised by Prince Louis of Battenberg and his children and nephews on 14 July 1917 after renouncing their German titles, due to anti-German feeling during World War I. They had considered an alternative translation, Battenhill, but later rejected it. The neighbourhood is named after Lord Louis Mountbatten (1900–1979).
Etymology from Wiktionary, CC BY-SA 4.0.