Ford: 83 camaro, battery cables, test light

Question
I have an 83 camaro. It has a new battery. If I charge the battery up the car will start for a day or so. I have had the charging system checked and it is all good. What else would cause the car to act like the battery keep dying?
Sometimes it runs then when you try and start it you get nothing. When you come back an hour later it will start again. Any ideas? Thanks

Answer
Stephanie what i would do first when you get the vehicle running leave it running and disconect the neg. battery cable and see if the car stays running if it does then the alt. and charging sys. is good.then next thing is to take a test light and go to the starter and the next time the car won't start put it to the solonid side of the starter have someone crank and if the test light lights up and the car doesn't turn over then the starter is no good. also ck your battery cables and see if there is any corrosion on the cable and ck the ends . Good Luck