What is in a Lead Acid Battery?

In a lead acid battery, the electrodes and grids are the main parts. Generally there is some other additive mixed in with the lead (like calcium) to offer it mechanical strength. The polarity of the plate is determined by the active material which is placed in physical contact with the grid. The active material is some formulation of lead oxides. Every battery producer has its proprietary formulation, often optimized for one performance characteristic or another. The electrolyte is sulfuric acid. Therefore the name is “Lead-Acid”.

The basic lead acid battery chemistry has been the workhorse of the automotive engine start and traction vehicle industries for quite a long time. When used in engine start applications, the batteries are referred to the acronym SLI, which is short for Starting Lighting & Ignition. Even within the last decade, lead acid still offers one of the most economic alternatives for many applications.