As much as I like Batman I wont sell Metallo short. Metallo one of Superman's deadliest foes who has knocked the Man Of Steel around would be a major threat in this fight. Metallo brings the strength to this fight and if he can keep it based on power I will give Metallo the win.
But for Metallo to use the strength he needs to be up close at Batman. Batman would need to keep a distance from himself and Metallo and hit Metallo hard with every weapon and high tech device he has. Since Batman's 127 fighting styles wont work against Metallo due to him being made of die hard steel.
The best strategy for Batman is to trick Metallo and get him to fall into a trap. Metallo might be die hard steel but he can be tricked and distracted. So if Batman can play a hit and move game, use smarts wether its prep or no prep he stands a chance of winning.
I think this would be a tough fight for both.