In case folk aren't aware the battery looks to be a 300 cycle affair just like most laptop and tablet batteries. So you will have battery issues eventually.
This thread started on 3/13/2013 so in your case it looks well inside the warranty which means it's no problem yet as you have the maker fix it.
All devices with batteries will have this failure and such a discussion will be found and be used as proof of a problem. And since we know batteries do this eventually, there is no dispute there is a problem.