A battery charging control device comprising a control circuit that performs control to keep a voltage across a battery charged by an output of an AC generator around a target value, comprising: a load driving switch inserted between the battery and a load; and a load driving switch control circuit that performs control to turn on the load driving switch when the AC generator generates the output and a voltage across the load is equal to or lower than a set value, and turn off the load driving switch when the voltage across the load exceeds the set value lower than the target value of the voltage across the battery.