How a Lead Battery is Recycled

Recycling a spent lead battery involves five basic steps:

The battery is broken apart in a hammermill, a machine that hammers the battery into pieces.

The broken battery pieces go into a vat, where the lead and heavy materials fall to the bottom while the plastic rises to the top. At this point, the polypropylene pieces are scooped away and the liquids are drawn off, leaving the lead and heavy metals. Each of the materials goes into a different “stream.” We’ll begin with the plastic, or polypropylene.

Plastic

The polypropylene pieces are washed, blown dry and sent to a plastic recycler where the pieces are melted together into an almost-liquid state. The molten plastic is put through an extruder that produces small plastic pellets of a uniform size. Those pellets are sold to the manufacturer of battery cases, and the process begins again.

Lead

The lead grids, lead oxide and other lead parts are cleaned and then melted together in smelting furnaces.

The molten lead is poured into ingot molds. Large ingots, weighing about 2,000 pounds are called hogs. Smaller ingots, weighing 65 pounds, are called pigs. After few minutes, the impurities, otherwise known as dross, float to the top of the still-molten lead in the ingot molds. The dross is scraped away and the ingots are left to cool.

When the ingots are cool, they are removed from the molds and sent to battery manufacturers, where they are re-melted and used in the production of new lead plates and other parts for new batteries.

Sulfuric Acid

Old battery acid can be handled in two ways.

The acid is neutralized with an industrial compound similar to household baking soda. This turns the acid into water. The water is treated, cleaned and tested to be sure it meets clean water standards. Then it is released into the public sewer system.

Another way to treat acid is to process it and convert it to sodium sulfate, an odorless white powder that’s used in laundry detergent, glass and textile manufacturing. This takes a material that would be discarded and turns it into a useful product.  Acid can also be reclaimed and reused in new battery products through innovative recycling processes.

Environmental Benefits

Lead batteries are the environmental success story of our time. More than 99% of all battery lead is recycled. Compared to 55% of aluminum soft drink and beer cans, 45% of newspapers, 26% of glass bottles and 26% of tires, lead-acid batteries top the list of the most highly recycled consumer product.

The lead battery gains its environmental edge from its closed-loop life cycle. The typical new lead battery contains 60 to 80 percent recycled lead and plastic. When a spent battery is collected, it is sent to a permitted recycler where, under strict environmental regulations, the lead and plastic are reclaimed and sent to a new battery manufacturer. The recycling cycle goes on indefinitely. That means the lead and plastic in the lead-acid battery in your car, truck, boat or motorcycle have been – and will continue to be — recycled many, many times. This makes lead battery disposal extremely successful from both environmental and cost perspectives.

Learn more in our Recycling and Sustainability Brochure

Recycling a Battery

Identifying Lead Batteries from Lithium-ion Batteries

There is serious risk of fire and explosion if a lithium-ion battery enters the lead battery recycling stream. While batteries can appear similar, it is important to make sure lead and lithium-ion batteries are properly identified and sorted. Use this flyer to practice safe recycling.

Recycling Rechargeable Batteries

One place that one can recycle batteries is Rechargeable Battery Recycling Corporation (RBRC). Consumers can recycle nickel cadmium, nickel metal hydride, lithium ion, nickel zinc and small sealed lead through their Call2Recycle™ program.

Battery Disposal Guide for Households

Environmental, Health, and Safety Online is an excellent resource on where to safely recycle used batteries for households and businesses.

Safe Transporting Information

The Pipeline and Hazardous Materials Safety Administration has created a resource used to inform consumers how to safely transport batteries.