The invention discloses a liquid fuel air heater. The air heater comprises a shell, an electric motor, a combustion chamber, a fan and a battery pack, wherein the shell defines a motor containing portion and a holding portion extending from the motor containing portion, the electric motor is positioned in the motor containing portion, the combustion chamber is at least partially located within themotor containing portion, the fan is driven by the motor and is configured to generate axial airflow passing through the combustion chamber when fan is actuated, the battery pack includes a pluralityof battery cells connected to one another in series or parallel arrangement, and the battery pack is detachably coupled to the holding portion of the shell to supply power to the motor.