I have iPad 3 when brought it it would not charge so ask apple come out have a look by time they were do to come it had charged up so canceled appointment since then its happened couple of times when I've accidentally let the iPad run out of charge completely ivehad it 4 years and its happened again its been on charge 48h now and all I get when I turn it on is red at bottom of battery and the charging sign which flickers on and of 3 times .does this mean I,need a new battery and if so how much will it cost thanks