The invention discloses a battery heating method and heating system and a battery. The battery comprises a battery roll core, a switch circuit and a heating device, wherein the heating device is arranged on an outer surface of the battery roll core, the battery roll core comprises a positive pole plate, a negative pole plate, a first separator, a positive tab and a negative tab, the positive pole plate and the negative pole plate are wound with each other, the first separator is arranged between the positive pole plate and the negative pole plate, the positive tab is arranged on the positive pole plate, the negative tab is arranged on the negative pole plate, the heating device is connected with the positive tab and the negative tab respectively, the switch circuit is connected in series between the heating device and the positive tab or the negative tab, and when the switch circuit is closed, the heating device releases heat after a current flows through the heating device so as to heat the battery in the battery. Through the abovementioned mode, the heat can be generated in an extremely low-temperature environment, so that the battery can normally charge and discharge in the extremely low-temperature environment.