Sounds like the battery wasn't fully charged when it was fitted,you changed it but don't say what with! a new one,on old one,one that wasn't powerful enough for the car,your problem started when you CHANGED the battery,go back to where you were,try the old battery back on first,you can get into all sorts of trouble if you start suspecting other faults because you thought the replacement battery was O.K.Retrace your steps.
Rich
September 2008