All battery components, when discarded, contribute to the pollution of the environment. Some components, such as paperboard and carbon powder, are relatively organic and can quickly merge into the ecosystem without noticeable impact. Other components, such as steel, nickel and plastics, while not actively toxic to the ecosystem, will add to the volume of landfill since they decompose slowly.
Of most concern, however, are the heavy metal components which, when discarded, can be toxic to plants, animals and humans. Cadmium, lead and mercury, in particular, are the heavy metal components most likely to be the target of environmental concerns.
Several of the major manufacturers have taken steps to reduce the amount of toxic material in their products. It is estimated that mercury usage in batteries had fallen from 778 tons in 1984 to 10 tons in 1995 in the US. However, battery manufacturing is still the largest single user of lead in the world.
Many of the major battery manufacturers have put significant steps into the recycling of discarded batteries. However, it still takes six to ten times more energy to recycle a battery to reclaim its components than to create the battery components from virgin materials. This cost differential will be steadily reduced in the future as a result of improvements in recycling technology that make battery recycling more energy efficient and cost effective.
The strategy of using secondary (rechargeable) batteries in preference to primary (disposable) batteries is one that benefits both the environment and the consumer. Over time. secondary batteries prove more cost efficient to use than primary cells. Even though the initial purchase price of secondary batteries are higher, they may be recharged and reused anything from 10 to 1000 times (depending on type) before they must be discarded, and the cost of a recharge is only a few cents. Ultimately, such multiple reuse will dramatically reduce the amount of discarded material from our landfills.
The most popular secondary batteries, however, contain cadmium. Many manufacturers, responding to customer requests and legislative demands, are designing nickel metal hydride, lithium-ion and rechargeable alkaline batteries that contain only trace amounts of cadmium, lead or mercury.
Tips for the environment-conscious battery user
The general guidelines of Reduce, Reuse, Recycle applies…
- Reduce battery usage by using AC adapters whenever possible, for example when using portable devices at home.
- Choose rechargeable batteries whenever possible over single-use batteries. The additional cost of rechargeable batteries and the recharger can be quickly recovered through savings from multiple use. Common secondary cells include nickel cadmium, nickel metal hydride, lead acid and rechargeable alkaline batteries. Success has also been reported in recharging ordinary (primary) alkaline and zinc-carbon batteries to a limited extent using special recharging techniques.
- Exercise consumer choice by buying non-toxic batteries (zinc carbon, alkaline, nickel metal hydride and lithium-ion) wherever possible in preference to batteries containing toxic materials (lead acid, nickel cadmium, mercury oxide). This will send a clear signal on consumer demand to manufacturers, and will also expand the market for non-toxic batteries, eventually reducing their cost.
- Eventually, when you have to discard your spent batteries, do so with care. If your battery contains toxic materials (lead acid, nickel cadmium, mercury oxide types), there are probably special toxic waste disposal facilities in your locality that you can use. Contact your local government department to inquire, or check the battery label or packaging for disposal advice.