wont start interior lights are dim and horn is week even w/ charger on start on 1992 Lexus SC400

My car wont turn when i tried to start it. I charge the battery and even jump it, it just click click click but inside it looks like the battery is dead the lights are dim and horn won't work. I'm sure i have the full power because I slide the battery charger button to start. Thanks.

Asked by for the 1992 Lexus SC400
How are the terminals, clean and tight? Check the ground cable where it mounts to the engine and body and make sure it is clean and tight..