From LEGO Batman Wiki
Batman's design changes significantly when the Power Suit is worn. Excluding his mouth, his entire head is now covered by his helmet, and the ears on the helmet are shortened also. He now wears orange boxing gloves, and the body and legs of his suit have orange on them as well. His cape is replaced by a mechanism with similar appearance to a jetpack that can shoot bombs. Because of the flat, orange look, this suit might be based off of the design of Clayface.
Upon utilizing the Power Suit, Batman gains super strength. This allows him to interact with heavy objects (objects with orange handles) and inflict more damage on enemies in combat. Also, he can shoot bombs (the player can set their target by pressing and holding the launch button) that eplode shortly after launch. These can be used to easily kill enemies and destroy silver objects. Batman cannot glide while in this suit due to the bomb shooting mechanism on his back replacing his cape. When the player presses the jump button while he is in midair, he will perform a dive instead.