Once the car battery has reached the end of its life, the question that arises is what should be done with it? Batteries contain a host of useful raw materials, and, because those materials aren’t biodegradable, the simple answer is to recycle the batteries. Recycling is now a legal requirement in many countries for all types of battery and automotive batteries are no exception.

 

​Recycling Lead-Based Car Batteries

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As the vast majority of car batteries (excluding some ultra-specialist models) are lead-based, there is a three step recycling model used to extract useful materials from them:

Stage 1 –  Separation

Once your battery has been received by a recycling plant, it will be placed into a machine known as a “hammermill”, which smashes the batteries into small pieces (about the size of a nickel).

These pieces are then placed into a tank of liquid where heavy materials (lead) sink, light materials float (plastics and rubber), and the acid goes into solution. This allows for easy separation of raw materials.

Stage 2 –  Lead and Plastic Recycling

The lead that’s removed during Stage 1 will be melted in a furnace, and then poured into moldings that allow for the formation of ingots.

While it’s molten, the impurities in the lead float to the top and can be removed to improve the purity of the finished lead product. In general, this lead is then sold back to battery manufacturers.

Rubber is removed from the plastic and the plastic is then washed and dried. It is then sent for melting and the plastic is then reset as a single piece which can be cut up and reused for battery manufacture. The rubber isn’t wasted – it’s used to add carbon to the lead produced in the same plant.

Stage 3 – Acid Addition

A neutralizing agent is added to the acid allowing a separation of water and chemical salts. The salts can be re-used for chemical production (including acid) and the water is purity-tested and then poured down the drain.