What is a Lead Acid Battery-How a battery is Made?

From lead alloy grid manufacturing to pasting, curing, assembly, formation charging and final quality checks, lead-acid battery production follows a controlled multi-stage process designed to ensure reliable performance and long service life.

The initial process begins with the manufacturing of grids from an alloy of lead mixed with a small percentage of other metals. The grids conduct the current and provide a structure for the active material to adhere.

Next, a paste mixture of lead oxide - which is powdered lead and other materials - sulfuric acid and water is applied to the grids. Expander material made of powdered sulfates is added to the paste to produce negative plates.

From there, a pasted plate will need to be cured. Curing typically takes place in a controlled environment with warm to high temperatures and modifying humidity for two to four continuous days. During this process, the crystallization growth occurs which binds the paste to the grids. Once cured, the plates are required to completely cool and dry.

Once the plates are ready, they will need to be alternatively stacked with a piece of separator between them. Separators are sheets of porous material that prevent short circuits, yet allow electrical current to flow between the plates. Once appropriately combined, all the positives are connected together, and separately, all the negatives are connected together. This combination of positives, negatives and separators combined is referred to as an element. The elements are then properly oriented and inserted into the battery case and welded together. Elements are typically arranged in series, in order for the two volt cell to reach six, 12 or whatever the intended voltage of the final battery.

Next, a cover is sealed to the top of the case, which contains the connected elements, and the terminal posts are formed outside creating an acid tight seal.

Since the battery construction is now complete, it can be filled with sulfuric acid or electrolyte and placed onto the formation charge. During the formation charge, the battery is connected to an electrical source and charged for many hours. Finally, once a battery is fully formed, it will endure various quality checks and be cleaned and labeled before arriving at a location for sale.