Click on the pushers to move the batteries. Your goal is to get the battery into the charging slot (with the blue and yellow brackets). Once the battery is in place, press the flashing play button to go to the next level. 

In later levels you'll have to use rotating tiles to make sure the battery is lined up correctly. The blue and yellow sides must match the orientation of the charging slot.

If you get stuck, press the restart button to try again.