it clearly has power but makes a weird sound which sounds very electrical so no click, click like before the battery died. All power works in car i.e. lights, window, radio, etc but it just seems stuck and i think it may need a computer reset but locking/unlocking doors did nothing, different key nada so any ideas would be great before I bite the bullet and tow the thing to the dealer. 2008 c30 t5. thanks all, hope a suggestion comes in because i am at a lose right now and can't afford the dealership and towing fee for a simple fix!

 

no one has any thoughts?!?

 

Were all the symptoms you described above similar when the old battery was in the car?
It is possibly an issue with the battery cables having a loose connection or maybe corrosion concealed under the insulating outer sheathing. A poor earth (ground) connection is also a possibility.
Also check the connections to the starter motor are ok.