Help loud clicking noise when trying to start

Help , long story however I'll keep it brief .
Taken 3 looooong weeks to change clutch folk in disco 1 ( during this time car hasn't been started ) . Finally got it back together , tried to start it and all I get is a loud clicking noise ( speed of a machine gun )
ANY IDEAS ?????
Car has always started first time every time .
Battrey on charger as I speak ....could be low on juice as alarm has been on .
Any other thoughts , I could be looking at whilest I wait .
Thanks in advance for any advice given

Flattery battery.

On the case thought it might be

Starter clicking but no battery power that is buddy

Spot on people , gave battery quick charge ......jobs a good one .

Nice one if you ever come back...