Please help me

Hi I have a 1993 chevrolet lumina I have had it for a year and 2 months. 2 weeks ago I started having problems with my car not starting so I charged my car battery and it work perfectly fine. I also have speakers conected. 2 days later the battery went dead so I went to auto zone again and I charged it fully so I decided to NOT hook up my speakers again because I thought that was the problem but, the same thing is happening only the battery lasted a week and it still works but the car turns off when I come to a stop light. I dont know what it could be please help me