An electric riding lawn mower comprising: a seat for a user to sit on; a main frame configured to support the seat; a power output assembly comprising a mowing element for outputting power to realize a mowing; a walking assembly configured to at least drive the electric riding lawn mower to travel in a first straight line on the ground and comprising a second motor to drive the walking assembly; and a power supply device comprising one or more first battery packs to power the electric riding lawn mower; characterized in that : the power output assembly comprises a first motor for driving the mowing element to output power; the first motor and the second motor are electric motors; each of the one or more first battery packs comprises: a first battery pack housing ; and battery cells disposed in the first battery pack housing; wherein the power supply device is mounted to the main frame, and at least one of the one or more first battery packs of the power supply device form a pluggable connection with the main frame, the battery cells are lithium batteries, and at least one of the one or more first battery packs is pluggably connected to the main frame and configured to power another power tool . a seat for a user to sit on; a main frame configured to support the seat; a power output assembly comprising a mowing element for outputting power to realize a mowing; a walking assembly configured to at least drive the electric riding lawn mower to travel in a first straight line on the ground and comprising a second motor to drive the walking assembly; and a power supply device comprising one or more first battery packs to power the electric riding lawn mower; characterized in that : the power output assembly comprises a first motor for driving the mowing element to output power; the first motor and the second motor are electric motors; each of the one or more first battery packs comprises: a first battery pack housing ; and battery cells disposed in the first battery pack housing; wherein the power supply device is mounted to the main frame, and at least one of the one or more first battery packs of the power supply device form a pluggable connection with the main frame, the battery cells are lithium batteries, and at least one of the one or more first battery packs is pluggably connected to the main frame and configured to power another power tool . the power output assembly comprises a first motor for driving the mowing element to output power; the first motor and the second motor are electric motors; each of the one or more first battery packs comprises: a first battery pack housing ; and battery cells disposed in the first battery pack housing; wherein the power supply device is mounted to the main frame, and at least one of the one or more first battery packs of the power supply device form a pluggable connection with the main frame, the battery cells are lithium batteries, and at least one of the one or more first battery packs is pluggably connected to the main frame and configured to power another power tool . a first battery pack housing ; and battery cells disposed in the first battery pack housing; wherein the power supply device is mounted to the main frame, and at least one of the one or more first battery packs of the power supply device form a pluggable connection with the main frame, the battery cells are lithium batteries, and at least one of the one or more first battery packs is pluggably connected to the main frame and configured to power another power tool . <EOS>