Heating apparatus, battery, and electric apparatus

A heating apparatus, characterized by comprising:

• a heating sheet, configured to heat a battery cell, wherein the heating sheet is arranged in a stretchable manner in a length direction of the heating sheet;
• and
• an adapting component, configured to connect the heating sheet to the battery cell, wherein the adapting component comprises at least two adapting bodies distributed along the length direction;
• and,
• wherein the heating apparatus is able to be switched from an initial state to a stretched state;
• in the initial state, along the length direction, a length dimension of the heating sheet is a first dimension, and two adjacent adapting bodies are connected;
• and
• in the stretched state, along the length direction, the heating sheet is stretched and extended from the first dimension to a second dimension, at least two adjacent adapting bodies are disconnected from each other, and the second dimension is a vertical distance between two end surfaces of the heating sheet along the length direction in the stretched state.