Well worst case if you have a bad battery and cannot get reasonable service then there are videos on U-tube about how to replace the battery and replacement S3 batteries are avalable from Amazon for under $30.
If under warrenty might obtain a RMA from Acer, ship just the battery and get Acer to ship a replacement. That way you could continue to use on mains power until the replacement arrives.
I just used BatteryInfoView to determine my W3 battery was bad and ordered one from Amazon. It is now working fine.