This is basically what hapepend to my son except for a few details (type of battery, where it got stuck, etc...) Copied this from a friend on Facebook. he's 6 and has been having breathing problems, and they couldn't figure out what was wrong. They found out he swallowed a calculator batter around a year ago - it has been lodged in his throat since then and had tissue grow up around it. it's now leaking acid into his system, and he's been in surgery for most of yesterday afternoon. He is in recovery now.