バッテリー
バッテリー · batterii · JLPT N1 · noun
battery
🔋 From English battery, from Latin battuere to beat, the same root as a battery of cannons firing together.
The English word first meant a group of cannons firing together, then a group of linked cells. バッテリー is the English word in katakana, with the long-vowel mark ー at the end.