156 dead battery
Hi Can anyone please help me? I have a 2003 156 2.0 jts and it has sat for 3 weeks unused, so the battery is flat! the central locking wont even open the battery is so flat! I opened it with the key and tryed to start it with a 12v emergency car starter! once conected and the ignition turned on all the lights go on ok but the car just makes a small week attempt to start but wont turn over! When i turn the sterio on it says code! I left the starter connected for 10 mins just to see if that helps but still no joy it just again makes a feeble attempt like its not getting any power! I would be really greatfull for any advise as i dont want to shell out on a expencive call out for something easly fixed if thats the case??