Battle Born is a passive module that activates a one-time defense system temporarily lowering all incoming damage when the robot is attacked. Upgrading this module increases the damage resistance bonus. If you use several modules of this type, the damage resistance bonus increases up to 60%. If you mount this module on the robots with their own defense systems (like Falcon), the bonus may be even higher.
Note: the resistance amount scales non-linearly. At some point, it becomes less effective and beneficial.
Battle Born, how defense works: