Could you add an external powered USB hub and provide power from an extra battery + regulator? That way the external battery would provide the necessary extra power for the Arduinos and you would only be using 1 USB port on your laptop.
Could you add an external powered USB hub and provide power from an extra battery + regulator? That way the external battery would provide the necessary extra power for the Arduinos and you would only be using 1 USB port on your laptop.