page 1 page 2
page 3
page 4
page 5
page 6
page 7
< prev - next > Energy recycling_batteries (Printable PDF)
Batteries are used whenever electrical energy is needed but there is no direct connection to
the public electricity grid. A battery can convert chemical energy directly to electrical energy.
Depending on the battery system, this converting process is irreversible or reversible. When
the process is irreversible, the battery is called a primary battery. The reversible batteries are
called secondary batteries and can be recharged up to 1000 cycles (i.e. lead acid battery-
checken). A lead acid battery is rechargeable and is commonly used as a result of its good
properties like low maintenance and suitable for many purposes. Furthermore they are easily
available and are relatively cheap.
Lead-acid batteries either start or power cars, trucks, buses, boats and trains all over the
world. This usage is well known but during the last years another usage is increasing. Solar
panels are becoming cheaper and an enormous boost is seen in the adaption of solar
applications in rural areas in developing countries where no electrical grid is available. As
lead acid batteries are still the cheapest way to store energy, almost all these solar
applications contain a lead acid battery.
However, lead is a very toxic metal and once the battery is not useful anymore, it is of the
utmost importance that proper collection and recycling takes place. In order to effectively
understand the issues about lead acid batteries in the solid waste stream and the benefits of
diverting them to recycling, it is important to know some technical aspects of the lead acid
battery, the public health and environmental risks associated with disposing of them,
recycling methods and relevant legislation developed to minimize risks involved with the use
and recycling.
Technical aspects
Lead Acid Battery cells consist of a lead (Pb) electrode and a lead oxide (PbO2) electrode
immersed in a solution of water and sulphuric acid (H2SO4). When the battery is connected to
a load and energy is generated, the lead combines with the sulphuric acid to create lead
sulphate (PbSO4), and the lead oxide combines with
hydrogen and sulphuric acid to create lead sulphate
and water (H2O). As the battery discharges, the lead
sulphate builds up on the electrodes, and the water
builds up in the sulphuric acid solution. When the
battery is charged, the process reverses, with the
lead sulphate combining with water to build up lead
and lead oxide on the electrodes (source:
Figure 1: Example of a lead acid battery
Practical Action, The Schumacher Centre for Technology and Development, Bourton on Dunsmore, Rugby, Warwickshire,
CV23 9QZ, UK
T +44 (0)1926 634400 | F +44 (0)1926 634401 | E | W
Practical Action is a registered charity and company limited by guarantee.
Company Reg. No. 871954, England | Reg. Charity No.247257 | VAT No. 880 9924 76 |
Patron HRH The Prince of Wales, KG, KT, GCB