He's hit 4 homers in about 100 at bats. If he gets another 400 over the course of the rest of the year, he should be at right around 20 by the end of the year if he stays at his current pace.
Honestly, I wouldn't be surprised at more. He's basically adjusted to the way the league pitched him. They saw he could hit the fastball, so they went offspeed. He's taking that to left and working walks, now they don't know what to do with him.
He's going to start crushing the ball. Crushing like Stanton, only better. He's going to be the best hitter on the team by the end of the year.