Modern lithium-ion batteries, widely used in EVs and solar storage, do not use sulfuric acid. Dominate 85% of the renewable energy storage market (BloombergNEF . The answer isn't straightforward—it depends on the battery type. Here's how they work: A mix of sulfuric acid and water facilitates ion flow between lead plates. Commonly used. OSHA and industry safety reports consistently highlight sulfuric acid as a key risk factor, making proper handling and regular inspection essential for battery safety. They are maintenance-free and do not need. The primary component of battery acid used in solar batteries is sulfuric acid ($H_2SO_4$).