If you use software such as Charge HQ, Myenergi Zappi or the Fronius Wattpilot EV charger to charge your EV from excess solar, these systems usually look for excess exports in order to tell the car to charge at that rate.
For customers with EVs and batteries using export control, we set the maximum export to 0.01kW~0.15kW to ensure your system sees enough 'excess solar' to allow charging for your EV or battery.