I was told such a small does of battery acid or etc. could not hurt me. could it increase my natural acid reflux as i do have a burning in my chest now?

I don't know who told you it was okay for small doses of battery acid, but that is not true. Even small doses can cause irritation of esophageal and bronchial tissues. Your chest pain could be symptoms of irritation of either or both of these areas. I suggest you see your primary or a GI doctor soon, a pulmonary doctor if you are having any respiratory symptoms such as cough, short of breath, etc

If it's from a car battery, Sulfuric acid is dangerous if ingested; it can burn on contact, causing tissue damage, even perforation of the esophagus and scarring of the mouth, throat, esophagus and lungs. It warrants an emergency visit to one's hospital or otolaryngologist (ear, nose and throat specialist).