I am experiencing a starting problem

I am experiencing a starting problem. On ocassion, when attempting to start, I get a clicking, rattleing sound as if the battery is dead. I charge the battery for a few minutes and the vehicle starts. I have replaced the battery with a new one and had the charging system checked. All have checked out fine. I was informed by a tech to replace the headlight switch as they have been known to cause such problems which I have done. I continue to have the problem.