What happens if you swallow a 9w battery or 4 1.5 battery's?

Something we don't actually know has something to do with what is in a battery what is it made of some you can recharge.I would think it could get stuck in your throat where you maynot be able to breath batterys are big and small there would be no way that you could swallow them without dieing so that would be what would happen if you tried to swallow them.