Battery electrolyte is pretty damned dilute sulfuric, I'd go to an industrial janitorial supply house, and get the toilet/clog remover, or drain remover. Don't ask for sulfuric, or they'll look sideways at you, just look around, you'll find it.
It's always labeled the "house" brand name, but you can tell what it is because it says "contains sulfuric acid", and is very, very heavy. Pure sulphuric acid is one of the very few that is much heavier by volume than water. The H2so4 (getting tired of writing it long form) sold there is >94% pure, a syrup really.
Last time I picked some up it was about ten bucks a liter.
When h2so4 is that pure it does something neat when you mix it half and half with a half cup of sugar, in a ceramic mug you'll never use again, and back away at least five feet, sometimes it starts to sputter after it gets going. (I used to be a chem major). It takes a few minutes to get going, and do it outside, it's stinky like burnt caramel (but not toxic).
If you don't need pure sulphuric, and I don't imagine you do, you'll have to mix it with water. Be careful, as diluting conc. H2so4 is exothermic, and can start the water to boiling and spitting.
Remember, acid to water is what you ought-to, water to acid is never placid.
You could use muriatic acid instead, but not only does h2so4 give you two protons per instead of one, as is the case with HCl, the HCl is going to offgas and rust every peice of iron/steel equipment in your shop.
Also, remember with HCL that no matter how dilute the sol'n, that the condensate on the underside of the lid and sides of the jug is going to be damned concentrated. My thumb turned black once. Of course that was a picnic compared to the time I left the stopcock open on a sep. funnel and poured some trichloromethane, and other assorted goodies into my lap (I was sitting), and took alot of the skin off the baby makers and the left side of my inner thigh.
Fun fact ..... despite ten years of university training, and vast quantities of safety gear and procedures, I was told that chemists still have shortest lifespans of all types of scientists. Remeber that when you're working with chemicals. Accidents don't happen when you get careless, they happen whenever they feel like it. Beleive it or not, I actually LOST an ounce of mercuric chloride in my apartment somewhere. It's a white crystalline powder, is tasteless, looks like sugar, is enough to kill a man a thousand times over in a horrible horrible way, and there's no antidote. I lost it a few years ago, and still can't find it. Somewhere in my cluttered apartment, or maybe with that stuff I put in storage.... I don't know. School was tough and I wasn't getting alot of sleep. I still worry about it. Thank god I don't have children or pets.
Did I mention that after two and a half years I switched to business and law?
