Have you ever wondered what happens to your old car battery when you get a new one? Chances are it gets recycled. Car batteries, also known as lead-acid batteries, are banned from landfills and incinerators in every state because they are so toxic. But, how does that battery get recycled, and what should you do if you replace the battery yourself? We have the scoop.

What is a lead-acid battery?

There are two types of lead-acid batteries: starting batteries and deep-cycle batteries. A starting battery quickly delivers a large burst of power to help an engine start. A deep-cycle battery delivers a continuous low level of power to help an engine keep operating. Lead-acid batteries were invented in 1859 by a French scientist named Gaston Plante and were the first rechargeable batteries used for commercial purposes. Plante and others used them to power lights on trains and help utilities store power. When most people think of lead-acid batteries they think of car batteries. But, the technology has many other uses. They are used in other vehicles such as boats, buses and golf carts. They power back-up generators at hospitals, prisons and other facilities during storms. Utility companies use them to handle fluctuations in energy demand and prevent power outages. True to their name, lead-acid batteries contain large quantities of lead and sulfuric acid. A set of lead plates, which represent the positive and negative sides, are lowered into an acid and water solution to charge the battery. Once the whole battery is built, it gets tucked into a plastic container to contain the metals, chemicals and their interactions with each other. Lead-acid batteries can hold their charge for years before the plates begin to wear down and the acid mixture begins to dilute. For a detailed explanation of how lead-acid batteries are made and how they work, visit Battery Council International’s website. A quick look at the contents of a lead-acid battery tells you just how important it is to recycle them. These batteries can seriously harm humans, animals and ground water supplies if their contents leak out of that protective plastic case. In addition, lead must be mined, which brings its own set of harmful environmental consequences.

How do lead-acid batteries get recycled?

According to the U.S. Environmental Protection Agency, specialized lead-acid battery recyclers crush old batteries into nickel-sized pieces and separate out the different components. The plastic in lead-acid batteries is mostly polypropylene (also known as PP or by the resin code #5), which has a high heat tolerance. It can be recycled. The lead in the batteries is sold to companies that make new batteries. The EPA estimates that up to 80% of the plastic and lead in any new battery you purchase is recycled.

Where can I take an old lead-acid battery for recycling?

Since lead-acid batteries are so dangerous, states have made it easy to get them to recyclers. Stores that sell new lead-acid batteries should take the old one and recycle it for you (nearly every state has a law that requires them to do so). Places that sell car supplies, such as Napa Auto Parts, Autozone and Firestore Complete Auto Care all offer recycling programs. The battery retailer Batteries Plus also accepts them (along with several other types of batteries and some small electronics, so see if you have anything else around the house you need to recycle before you visit your local store). Check with locally owned retailers in your area to see if they recycle lead-acid batteries. Household hazardous waste facilities should also accept lead-acid batteries for recycling. Call ahead to find out when your local hazardous waste center is open and if it has any fees. In some places household hazardous waste facilities are open nearly every day, while in other communities they only open for collections once or twice a month. Many towns have made hazardous waste drop-off free to encourage people to bring in materials rather than dumping them, but some charge a small fee for the service. When you remove a lead-acid battery from your vehicle, leave the lead cable ends attached. Check the battery to make sure it is not leaking. If it is, immediately place it in a leak-proof container (you can buy special battery boxes made of Fiberglas or plastic at auto parts stores). Battery acid can eat through concrete, so if you must put it on the ground, see if you can find a sealed asphalt surface. Clean up any leaks with lime or baking soda (the cleanup materials must then also be treated as hazardous waste). While transporting the lead-acid battery to a recycler, place it in a leak-proof container and make sure you keep it upright so the acid cannot leak out. If you have more than one battery, separate them with a piece of wood or another material so the post terminals do not touch each other.