I have heard different prices for the main hybrid battery â from several thousand new, to potentially $1500, according to one person, who found a low-mileage battery in a junkyard. The 12V battery, including labor, cost me roughly $280 to replace; my Prius is a 2011 3rd Gen, and from what Iâve researched, this is about the time that the 12v can be expected to die.