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Technical Support > Battery Care & Maintenance

Battery Care & Maintenance


Taking good care of your battery will help to extend it's service life. For tips on how to keep your battery in top condition, please follow the links below.

Regular Inspection and Maintenance

Regular testing and inspection will help to maximise battery life. A routine inspection at least once a month is recommended to maintain optimum performance.

Use the following as a guide when examining your battery:
 
1. Ensure the battery top is clean and dry, free of dirt and grime. A dirty battery can discharge across the grime on top of the battery casing.
 
2. Inspect the terminals, screws, clamps and cables for breakage, damage or loose connections. These should be clean, tight and free of corrosion.
 
3. Apply a thin coating of high temperature grease to posts and cable connections for added protection.
 
4. Inspect the battery case for obvious signs of physical damage or warpage. This usually indicates the battery has overheated or has been overcharged.
 
5. Check electrolyte levels to ensure that fluid levels are over the top of battery plates. If necessary top up using distilled or demineralised water. Never top up fluid levels with acid.
 
6. Test the battery using either a hydrometer or voltmeter and charge if necessary.
 
If you are unsure about the condition or state of charge of the battery, take it to your local Century battery reseller.
 
They can inspect and test your battery and provide you with professional advice and assistance.
 

Battery Testing

Battery testing should form part of a regular maintenance routine. Pre-emptive battery replacement can help eliminate many of the costs and problems associated with a flat battery.

Voltage and Specific Gravity

Voltage (V) and Specific Gravity are measurements used to determine a battery’s state of charge. Voltage is a quick and easy way of measuring charge levels and is measured by connecting either a multi-meter or voltmeter and obtaining a DC reading. Always connect the multi-meter parallel to the circuit being tested,  observing polarity; otherwise the result will be negative.
 
Hydrometers measure the Specific Gravity of the electrolyte and indicate the density of electrolyte compared to water. As this requires access to acid reservoirs, it is only suitable for use with maintainable batteries.

Testing Methods

Unloaded Testing

This is performed using either device, when there is no current draw on the battery. A specific gravity reading of 1.275 to 1.290 shows a full charge whereas a reading below 1.240 indicates that the battery should be recharged. If the stabilised open circuit voltage is below 12.55V, this also indicates recharging is required.

Low Load Testing

This is conducted using a multi-meter or volt meter whilst running an accessory, such as the  headlights, and taking a voltage reading. The battery in a 12V system should have at least 11.5V DC with the lights on. If the voltage drops below this level, the battery needs charging.
 

Battery Charging

Always read the manufacturer’s instructions before attempting to charge a battery and ensure you have a good quality battery charger. The battery type and its internal components will determine which type of charger is required.
 
Important Note:
Avoid quick charging as this only charges the surface of the battery plates and can increase the chance of overheating, leading to permanent battery damage.
 
Be aware of all safety precautions that should be observed during the charging operation before attempting to charge a battery.
 
1. Turn the charger off before attaching, rocking or removing the terminal clamps.
 
2. Keep open flames and sparks away from the battery.
 
3. Keep vent caps in place.
 
4. Charge in well ventilated area.
 
5. Follow the battery charger manufacturer’s instructions to avoid overheating.
 
Specific charging rates or times are difficult to detail due to a number of other features, such as:
 
1. The electrical capacity of the battery.
 
2. Temperature of the electrolyte.
 
3. Battery state of charge at the start of the charging period.
 
4. Battery age and condition.
 

Factors Affecting Battery Life

As batteries age they gradually lose their capacity as their function is performed. The constant charge and discharge eventually leads to failure. Components corrode over time, electrical shorts occur and vibration causes damage; all eventually causing failure. Overcharging and undercharging of a battery will also have a bearing on battery life.

Battery Inspection

Check electrolyte level - fluid below the tops of the separators indicates overcharging or poor maintenance. Overcharge condition may be due to incorrect voltage setting, low voltage caused by heat or internal defects, or old age deterioration.
 
Is there electrolyte on the top of the battery? This can indicate overcharging or over filling.
 
Is the battery loose in the carrier? This can cause failure from vibration.
Has the battery signs of damage or mistreatment? This can also cause failure.

Discharged (flat) Batteries

A flat battery should be checked with a hydrometer. A low Specific Gravity reading of 1.220 or less in all cells indicates a discharged battery and it must be charged before further examination and testing can occur. The discharged condition may be due to a problem in the electrical system (slipping alternator belt, faulty regulator or alternator, high resistance due to corrosion). Internal shorts may also be due to manufacturing defects or shorts through the ageing process or vibration damage.

Early Warning Signs

Batteries often fail when least expected. The usual warning is a slower than normal battery ability to crank the engine. Other less noticeable factors, such as changed driving patterns and colder/hotter weather will all have an effect on the life of a battery. We encourage you to ask for a ‘FREE Battery Test’ at your local Century battery stockist. This is a great preventative mainatenance check and if the battery is near failure, it may avoid the inconvenience of a roadside breakdown.
 

Technical Tips

  • Vibration can reduce a battery’s life. Always use an approved battery clamp to limit vibration. Century batteries are built tough, using robust internal components to resist damage through abrasion and puncture from vehicle vibration.
     
  • Many alleged ‘dead batteries’ are merely flat batteries. Drivers simply leave lights on or can have faulty voltage regulators.
  • Ensure your battery is properly tested before replacing a battery.
     
  • It’s impossible to know exactly when a battery might fail. A slow starting engine is sometimes an indication.
  • Old batteries can give trouble in colder weather.
  • Equally, if an engine area becomes overheated in very hot weather and the battery is under current draw strain from air conditioners it may fail. Regular battery checks are always advised.