The Anti-Aircraft Battery is the second type of mobile anti-aircraft unit. It becomes available in the Modern Age and is built at the Factory. The Anti-Aircraft Battery is an upgrade of the Industrial Age Anti-Aircraft Gun. By upgrading it receives +40 hit points, +1 attack strength, +3 attack range, +8 movement speed, and +3 line of sight. In the Information Age, this unit upgrades to the final type of anti-aircraft, the Anti-Aircraft Missile.