MCU Ultron vs Arkam Knight Batman team

I'm unfamiliar with Arkham Batman's prep prowess, but I'd assume he and his team could fashion something pretty darn effective given a month, and could certainly hide the activity from Ultron's prying eyes. They also have just under a month to hide their setup from Ultron. In a hand to hand fight the team would obviously be demolished, but given the prep time I'd give it to the team.

Ultron nukes them.

They can't put Ultron down.

The Batman Family has never faced a robot of Ultron level. Even with the Batmobile they can't hurt him. Even with prep they have nothing that good enough to harm him.