The Ballistic Augmented Tactical Armorsuit - also known as the B.A.T. Armor - was a suit of armor designed for Bruce Wayne by Tony Stark, after Tony learned Bruce's identity as Batman when Bruce talked him out of committing suicide.
While the Iron Man armor was designed to simply focus on raw power, the B.A.T. Armor was designed with a focus on allowing for the user to engage in hand-to-hand combat. It was equipped with an augment mode to push it to greater extremes, as well as modified versions of Batman's standard equipment such as Batarangs and Grapnels, but could be dangerous to Batman's heart and lungs if used for prolonged periods.
The B.A.T. armor was given a field test when Ezekiel Stane attempted to take control of Stark's other armors to sabotage Tony's new arc reactor project. The armor provided a significant advantage against Stane as he couldn't take control of it without rendering it ineffective.