Aside from the battery removal, this is just another good example of why you never check a bag. The battery issue is a snafu and you will likely be able to push for a bit more remediation but expecting a free Mint seat is a little DYKWIA. I've posted about my issue with gate checking recently and once again this steers more of my flying away from B6. Also, not to harp, but there are a ton of articles, posts, and stories about these brands of smart luggage and the need to avoid checking them.