HUDDERS1

I have just got home from two weeks away, just been to start my2007 wrx and the key would not turn of the alarm so open door with the key and the alarm did not go off. I then tried turning the car over nothing so i disconnected the battery and started charging. The led on the charger showed it had 50% charge would this be enough to at least work the alarm it not the battery?
thanks in advance
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