The word батарея is simply translated as battery, and just as in English, it can refer to a few different objects. First, to a battery that is used to run electronic equipment, which Russians often call батарейка. Then, to a military battery, as in an artillery unit grouped on the battlefield for better tactical maneuvering and action. Thirdly, it labels the radiator, part of the traditional heat transfer system that warms all Russian apartments and houses by hot water and steam circulation in the winter, late fall and early spring.

Image of a radiator from http://obninsk.name