What Happened?

I just went out to pull my 65 Barracuda Formula S in the garage to install a new set of leaf springs. I have been busy for the last 2 weeks so the car has sit outside. Before that I rebuilt the front suspension and replaced the master cylinder. The car started on its own and ran ok. Today it is dead. I hooked up a charger thinking I left a light on or something and the battery shows a full charge. I have no lights no horn or anything. Tell me what to check, I would like to get it in the garage to start the rear springs before the rain starts on tuesday evening.
Thanks for your help.