Hi I just got of the phone with Nintendo. I have a customer who's N3DS XL seems to overheat and freeze while playing "heavy" games. Like Hyrule Warrios Legends. I checked the console, its updated to the latest firmware version. I did a visual check of the battery, and it seems to be ok. I know some batteries could "puff up". The strange thing is. I asked the Nintendo Rep if I should Format System Memory before shipping it in to them. They would not recommend me doing so, as the customer would loose all of her progress. I mentioned using the built in Save Data Backup feature. He claimed the saves would not be accessible after doing a Format System Memory. Now, I asked him "Why do you have such a feature, if it doesn't work?" He giggled, and went on to state that it had something to do with security and fear of piracy. So now I really dont know what to do. Can someone confirm that it is safe to use the tool found here: Settings -> Data Management -> Nintendo 3DS -> Save Data Backup, to backup the saves. I would copy the .sav files to a PC (so they don't get deleted somehow), then move them back to the 3DS. The menu has a "Restore" button, as well as Backup and Delete. I must say, I don't know if the rep knew what he was talking about or not. Thats why I come here. Now it seems as tho I will have to be playing Hyrule Warriors Legends all night, hoping for a console freeze so I can record it and send to Nintendo.