The Most Common Reasons Why Car Batteries Fail

Car Battery FailureA battery is one of the most fundamental components that make a vehicle start and run smoothly. Although created to withstand severe conditions, not every brand is specifically designed to handle the extreme environment that motorists in Australia often experience. Hence, car batteries fail unexpectedly, especially in Sydney’s bumper-to-bumper peak driving environment.

The country’s climate varies from place to place, but in some areas, temperatures can rise from 25 to over 50 degrees centigrade. In a rough driving environment, temperatures like these could contribute directly to the breakdown of the physical components of batteries.

The warm Australian climate makes the batteries electrolyte solution corrosive as it gets hotter. As a result of this increased chemical reaction, the lead components are eaten away faster or reacting internally causing sulphation layers on the plates which inhibit electric current flow.

Car Batteries Fail Prematurely In Higher Under-Bonnet Temperatures

Basically, for every 10 degree increase in temperature, the chemical reaction within a car battery is doubled thus causing a more corrosive “Acid Soup.” This is more of a concern, especially in milder and hotter conditions such as that experienced here in Australia. Century Batteries undertook a study of under-bonnet temperatures in late model Ford Falcons and Holden Commodores in variable driving environments of Sydney and Melbourne.

It was concluded that there was a range between 73 and 85 degrees within an ambient temperature range of 28 to 37 degrees. Another interesting fact, was that cooler outside temperatures had little or no effect in cooling the hot under-bonnet temperatures. However, the statistics show that city driving in the hotter summer months increased the temperatures exponentially, thus increasing the corrosive nature of a battery.

To understand how extremely important it is to use only car batteries that are specifically designed for the Australian climate, here are some other top reasons why batteries suffer from premature damage:


In many parts of Australia, batteries are subjected to high temperatures under the bonnet. With the heat, battery acid, which is already corrosive by nature, becomes increasingly so. As such, it tends to eat away at the critical internal components of the batteries, which are made from metal alloys. This then, results to early internal damage and eventual car battery failure.

Water loss

It is natural for automotive batteries to lose moisture even in ideal conditions because of gassing. But, just like a “Water Kettle”, as temperatures increase, the rate of gassing/evaporation also increases, and as a result, batteries lose water at a faster rate. The Century Sealed Maintenance Free Range, are engineered with superior internal components and materials to minimize water loss in all types of conditions.


Automotive batteries are subjected to strong vibrations when a car is used on rough roads. Vibration can cause damage to the internal components of the vehicle’s battery and can even lead to cracks and degradation of the active paste material on the plates. Unfortunately, the roads in Australia, which we are all very aware of, are not of the highest standard and vibration is a common problem.

Idling and city gridlock driving conditions

Idling, such as when the engine is allowed to run during traffic jams or when a vehicle is driven at slow speeds for long distances can contribute to premature battery failure. The loads placed on a battery in these conditions are quite extreme, causing irreparable damage.

Why does the robust construction of batteries matter?

Australia’s harsh weather and city gridlock driving conditions, combined with rough roads, can vibrate and stress critical components within a battery. They should be designed for our conditions in mind, with components able to withstand excessive corrosive effects and vibration resistance.

Exposure to the elements is unavoidable for most batteries, so it’s critical that motorists choose the right kind of product that is specifically built for extreme conditions. Our choice is Century Batteries, a brand that has been on the forefront for over 85 Years here in Australia, developing innovative batteries that meet the expectations and demands of motorists nationwide.


In concluding, the rate at which car batteries fail is exponentially increased with constant idling and stopping in gridlock city driving environments. In these conditions, under-bonnet temperatures and insufficient charging are dramatically increased, therefore increasing the corrosive nature of the battery acid which degrades the internal components rapidly.

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