A battery charger comprising: a housing including a plurality of charging ports, each of the plurality of charging ports configured to receive a battery pack; a power supply module electrically connected to a power source and configured to supply power to the battery charger, wherein the battery charger operates in a first operational power mode and a second operational power mode; a controller configured to: determine whether one or more of the plurality of charging ports is to receive a first charging current, determine whether one or more of the plurality of charging ports is to receive a second charging current, wherein the first charging current is greater than the second charging current, operate the battery charger in the first operational power mode when one or more of the plurality of charging ports is to receive the first charging current or the second charging current; the battery charger being further characterised in that the controller is further configured to execute a charging control process, the charging control process including: generating a charging signal to enable one of the plurality of charging ports to receive the first charging current or the second charging current when the one of the plurality of charging ports is to receive the first charging current or the second charging current, and operating the battery charger in the second operational power mode when none of the plurality of charging ports is to receive the first charging current or the second charging current. a housing including a plurality of charging ports, each of the plurality of charging ports configured to receive a battery pack; a power supply module electrically connected to a power source and configured to supply power to the battery charger, wherein the battery charger operates in a first operational power mode and a second operational power mode; a controller configured to: determine whether one or more of the plurality of charging ports is to receive a first charging current, determine whether one or more of the plurality of charging ports is to receive a second charging current, wherein the first charging current is greater than the second charging current, operate the battery charger in the first operational power mode when one or more of the plurality of charging ports is to receive the first charging current or the second charging current; determine whether one or more of the plurality of charging ports is to receive a first charging current, determine whether one or more of the plurality of charging ports is to receive a second charging current, wherein the first charging current is greater than the second charging current, operate the battery charger in the first operational power mode when one or more of the plurality of charging ports is to receive the first charging current or the second charging current; the battery charger being further characterised in that the controller is further configured to execute a charging control process, the charging control process including: generating a charging signal to enable one of the plurality of charging ports to receive the first charging current or the second charging current when the one of the plurality of charging ports is to receive the first charging current or the second charging current, and operating the battery charger in the second operational power mode when none of the plurality of charging ports is to receive the first charging current or the second charging current. generating a charging signal to enable one of the plurality of charging ports to receive the first charging current or the second charging current when the one of the plurality of charging ports is to receive the first charging current or the second charging current, and operating the battery charger in the second operational power mode when none of the plurality of charging ports is to receive the first charging current or the second charging current.