The automotive battery provides starting power for the engine. It also supplies power to accessories such as lights, fans and radio when the engine is not running.
Between low engine speeds and when accessory load is greater at higher running speeds, a battery makes up the difference by stabilising the alternator output.
This stabilising effect also protects a vehicle’s electrical system by smoothing out sudden high voltages which can damage electrical components.
Batteries produce their power through a chemical reaction which is released when a load such as a globe, starter motor or electric fan is connected to the battery. Electrical current is generated when two different metals are placed separately in a liquid capable of conducting electricity.
When the metals are connected together above the liquid, electrical current flows through the connection. The different metals are referred to as electrodes. Pure lead is used for the negative electrode or plate and a lead dioxide paste is used for the positive electrode.
When a positive and a negative electrode are combined (but not touching), they are referred to as a cell. Two or more cells connected together are called a battery.
The positive and negative plates are always separated by a separator to the plated, they do not make contact and self-discharge. The liquid solution is called an electrolyte which consists of a diluted solution of sulphuric acid.
The battery becomes discharged (or flat) when no more current flows through the cell. The cell can be recharged by forcing electrical current back through the cell in the reverse direction. The chemical reaction that takes place during discharge converts both the positive electrode and the negative electrode to lead sulphate.
Water is produced and dilutes the strength of the acid. During recharge, the electrodes are converted back to lead dioxide and lead. The water produced during discharge is consumed returning the lead to its original strength. In addition, some electrolysis of the water in the electrolyte occurs breaking it down into its component gases: hydrogen and oxygen
Batteries must be subjected to regular testing to ensure their starting capacity is maintained at an optimum performance level.
A battery must also be scrutinised for any physical condition which may reduce battery life and impede starting performance such as broken or damaged posts and leaks to the battery case or lid.
The first step in evaluating starting capability involves testing a battery’s state of charge using a hydrometer or voltmeter. All non-sealed batteries should be checked using a hydrometer. As a cheap and reliable method of determining state of charge, the hydrometer also reveals differences between cells and allows visual inspection of the electrolyte colour.
Where the hydrometer reading shows no significant difference between cells and produces a reading of 1230 or above (at 20-25 C) the battery has sufficient charge for a load test. Sealed batteries must produce a voltage of 12.5 or greater before a load test may be performed. Since the loss/fail criteria varies depending on the make of load tester used, be sure to consult the instruction manual provided with the tester to ensure success.
- Ensure appropriate safety glasses and clothing are worn at all times before installing or removing your battery
- Always refer to Vehicles Operating Manual before removing or installing a battery
- Check bonnet clearance before installing battery.
- Connect memory minder (to avoid the loss of radio pin codes and key vehicle data). Keys must be removed from the vehicle.
- Locate the positive terminal and mark polarity on the cable.
- Remove the negative cable first..
- Remove the positive terminal. Remove battery hold down.
- Inspect the tray for corrosion. If necessary, dust off corrosive residue.
- Place the new battery in the tray and ensure the battery is level and the terminal posts are in the same position as the old battery.
- Replace the hold down clamp and ensure battery is secure.
- Replace the positive terminal lead and tighten.
- Replace the negative terminal lead and tighten. (The negative terminal should always be replaced last)
- Never tighten or hammer terminal onto the battery as this can damage the posts and battery cover and will void the warranty
With today’s modern vehicle electrics and charging systems, don’t leave things to chance. If you need your battery tested or professionally installed call us.
Before charging begins, provide plenty of ventilation and ensure safety glasses or face shield are worn. Sparks from loose connections or metal tools making contact between the terminals or the un-grounded terminal and nearby grounded metal parts can also be hazardous. Do not remove the vent caps (maintainable product only) and do not charge the battery unless you are thoroughly familiar with the step-by-step procedure of recharging a battery. Ensure you have read the manufacturers instructions for the specific charger you are using prior to commencing the charging procedure.
- For maintainable battery types only – loosen the vent caps and then place a damp cloth over the vent caps, prior to commencing. For maintenance free product, continue to step 2.
- Connect the charger leads to the battery terminals, red positive (+) lead to positive terminal and black negative (-) lead to the negative terminal. Rock the charger lead clamps to make certain a good connection has been made.
- Set the electric timer to the desired charge time
- Turn on the charger and slowly increase the charging rate until the desired ampere value is reached. Do not charge in the red zone. If the battery starts to emit smoke or dense vapour, shut off the charger and reject the battery. If violent gassing or spewing of electrolyte occurs, reduce or temporarily halt the charging. Never touch the charger leads when the charger is ON. This could break a connection at the battery terminal and create a spark which could ignite the explosive gases in the battery. Never break a ‘live’ circuit at the battery terminal for the same reason. Always turn the charger OFF before removing a charger lead from the battery.
Before charging begins, provide plenty of ventilation and ensure safety glasses or face shield are worn. Sparks from loose connections or metal tools making contact between the terminals or the un-grounded terminal and nearby grounded metal parts can also be hazardous. Do not remove the vent caps (maintainable product only) and do not charge the battery unless you are thoroughly familiar with the step-by-step procedure of recharging a battery. Ensure you have read the manufacturers instructions for the specific charger you are using prior to commencing the charging procedure.
- For maintainable battery types only – loosen the vent caps and then place a damp cloth over the vent caps, prior to commencing. For maintenance free product, continue to step 2.
- Connect the charger leads to the battery terminals, red positive (+) lead to positive terminal and black negative (-) lead to the negative terminal. Rock the charger lead clamps to make certain a good connection has been made.
- Set the electric timer to the desired charge time.
- Turn on the charger and slowly increase the charging rate until the desired ampere value is reached. Do not charge in the red zone. If the battery starts to emit smoke or dense vapour, shut off the charger and reject the battery. If violent gassing or spewing of electrolyte occurs, reduce or temporarily halt the charging. Never touch the charger leads when the charger is ON. This could break a connection at the battery terminal and create a spark which could ignite the explosive gases in the battery. Never break a ‘live’ circuit at the battery terminal for the same reason. Always turn the charger OFF before removing a charger lead from the battery.
Possible causes of battery failure that are not the result of faulty manufacture:
- Incorrect or under-specified battery type fitted to car
- Charge system problem (low or high voltage) creating an over-charge or under-charge situation. A low voltage cause the battery to sulphate whilst a high voltage will literally cook the internal components of the battery.
- Repeated deep discharge (heavy accessory loads, car phones, lighting, boat accessories, etc)
- Prolonged storage of the car or very minimal use. A battery will generally sulphate and will never recover its full state of charge.
- Electrical faults (short, excessive loads)
- Any battery modifications such as acid additives, lead terminal changes, or any other contaminates.
- Damage to the battery caused by the consumer or other in-car fault.