BATTERY

A battery includes a battery casing and a cell. The battery casing is provided with a liquid injection hole, and the cell is disposed in the battery casing. The cell includes a cell body and a tab portion. The tab portion extends from a side surface of the cell body, the liquid injection hole is located on a side of the cell body adjacent to the tab portion, and the liquid injection hole is disposed on a surface of the battery casing opposite to a larger surface of the tab portion. In a direction perpendicular to an extending direction of the cell body and the tab portion, a minimum vertical distance between the liquid injection hole and the tab portion is a, and a width of the cell body is b, where 5≤b/a≤20.