Bought the laptop few months ago did not use it over a month , today try to switch it on and find battery dead . Put AC on but battery orange light on about 10-15 min then keep flashing and check the battery still 0 % over a hourand won't charge at all. also what the different between battery of ACER Aspire One Blue ZG5 UM08A51 and ACER Aspire One Blue ZG5 UM08A73 please help