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Batteries


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More battery information

The battery in your car is rechargeable and supplies electric energy to power the starter motor, the lights, entertainment system and the ignition system of the vehicle's engine.

Automotive batteries (often referred to as lead-acid batteries) are made up of plates of lead and lead dioxide, which are submerged into an electrolyte solution of about 35 per cent sulphuric acid and 65 per cent water - the result is a chemical reaction that produces electricity.

The battery's ability to supply high surge currents means that the cells maintain a relatively large power-to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.

The battery stores energy to be release to start your vehicles engine. Once the engine is started, your car's battery is recharged by the engine-driven charging system or alternator (if a battery is discharged i.e. lights left on it must be benched charged to restore to full capacity). Corrosion at the battery terminals can prevent a car from starting, by adding electrical resistance so it is important to clean the terminals periodically using water and a wire brush. Ensure you wear the correct protective gear (gloves and eye protection) as the white powder (lead sulphate) is toxic if inhaled, ingested or contacts the skin.

Common battery faults include:

  • Shorted cell due to failure of the separator between the positive and negative plates
  • Shorted cell or cells due to build up of shed plate material below the plates of the cell
  • Broken internal connections due to corrosion
  • Broken plates due to vibration and corrosion
  • Low electrolyte
  • Cracked or broken case
  • Broken terminals
  • Sulfation after prolonged disuse in a low or zero charged state

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