An aspect includes a battery charging system for a hybrid electric aircraft. The battery charging system includes a generator, a battery system, and a controller. The controller is operable to charge the battery system up to a first charge level based on receiving a first charging current at a power input. An operational status of a gas turbine engine of the hybrid electric aircraft is monitored. The battery system is charged at a second charging current received from the generator driven by the gas turbine engine responsive to determining that the gas turbine engine is in a taxi state, where the second charging current is less than the first charging current. Charging of the battery system is halted based on detecting a transition of the gas turbine engine from the taxi state to an off-idle throttle state.