Context would help. It's probably a phrase from baseball. The batter is the person who attempts to hit the ball. It's often used metaphorically when someone attempts something several times and repeatedly fails and gives up.

I do not recognize this, I don't think this is a commonly used phrase because I couldn't find it on Google!! :p

Batter out is a sports phrase that means the batter (person batting the ball) is out (as per the rules of the game) It's also used rarely in American slang to mean you're out in any situation.

"Batter out" is not standard usage in American English either. Perhaps the phrase was taken out of context, such as: "Take the batter out from the fridge." Here, batter = a semiliquid mixture of flour, eggs, and milk. Or: "The umpire called the batter out." Here, batter = a baseball batter, and the phrasal verb is "call out" not "batter out." In other words, the sequence "batter" + "out" is possible, but it is not a standard phrasal verb in English.