When I was a budding bullet caster in high school or college I remember reading that you could get the lead out of a car battery by pouring out the acid, filling it with water, putting it into the fereezer for a few days then smash it on the driveway where all the plastic, tar and ice will seperate and leave the screens of lead for the melting. Well, I did that and it didn't shatter that well. I needed a sledge hammer to bash it up and eventually got some lead like metal screens from the mess in the driveway. Once melted (outside) I got something I could cast but the round balls were grainy and would actually crack when struck by a hammer rather than just flatten. It was lousy, hard, mealy "lead". It might make OK slingshot ammo but I eventually melted it into a big batch of pistol bullet lead and got rid of it by casting it up & shooting it. I only got a few ounces of "lead" from the battery. It's too labor intensive for poor casting sort of "lead". Don't waste your time with it. Take it to a scrapper and get real lead with the cash or trade.