The car battery in an internal combustion engine (ICE) car is a rechargeable, electrical storage unit that is designed to deliver a burst of electric current that enables a vehicle to start. While that is its main task, the battery is also used to power a vehicle’s accessories such as lights, the entertainment system and everything else that can be activated when the engine is off.
Once the engine is running, power to the car’s electrical system is provided by the alternator which also delivers a current back to the battery for it to recharge.
The most common type of battery in ICE cars are traditional lead-acid units known as Starting-Lighting-Ignition (SLI) batteries. Most of these SLI batteries are now maintenance-free, meaning that the unit is closed and the task of checking electrolyte levels and adding water to the battery – once a standard maintenance job for every car owner – is no longer required.
While LSI batteries are the most common type of battery in use, such is the development in the automotive industry that many new ICE cars come loaded with devices, accessories and features – such as stop-start technology – that place a much higher demand on the battery. Consequently, the type of battery used in modern vehicles may be different. These alternative battery types include gel batteries, calcium batteries, or absorbent glass mat (AGM) batteries, all of which are designed to deliver more power over a longer period and weather longer and deeper discharge and recharge cycles.
SYMPTOMS OF BATTERY FAILURE
Whichever battery is fitted to a vehicle, when they start to fail, symptoms are pretty similar. Most obvious is that the vehicle won’t start, or accessories won’t activate, indicating the battery is ‘dead’. If the battery is not quite exhausted but is on its way out, then symptoms would include difficulty in starting the vehicle, lights that are dim, and accessories that are barely functional.
HOW LONG SHOULD A BATTERY LAST?
A battery that is well-maintained and in good condition should last around four years. However, the lifespan will depend on some outside factors including how often the vehicle is used (as with any component, heavy use will shorten a battery’s useable life) and the environment in which it is used. All batteries are strained by extremes in temperatures, and if the electrical system of which it is part is not reliable, that too can affect the battery too. The number of components and accessories that it may be expected to charge or run can also affect battery life, as can the types of journey undertaken – if all that is asked of a vehicle is that it do multiple short trips a day, then the battery is being stressed and drained to deliver that big burst of ‘starting’ energy without the driving time needed for a decent recharge.
WHAT TO DO IF THE BATTERY IS FAULTY
It should be noted that if a vehicle is having trouble starting, the culprit may not be the battery (although it often is). Instead, the starter motor – which absorbs that burst of electrical energy from the battery and is the actual, physical device that kickstarts the engine – may be at fault. Also, if the battery is actually ‘dead’, the cause might be the alternator, which may be faulty and failing to recharge the battery properly.
Determining the exact problem requires the expertise of a qualified mechanic or auto-electrician. If it should prove to be the battery that is faulty, an experienced technician will replace it correctly. And that is important. The installation of the wrong type of battery, or if the battery is fitted incorrectly, can cause serious damage to a vehicle’s electrical system, resulting in a very expensive repair job. It can even be physically dangerous if the right procedure isn’t followed.
Remember that a car battery replacement is a relatively inexpensive undertaking. A battery may cost from around $150 for a common SLI type to several hundred for the powerful deep-cycle AGM batteries, but that is considerably cheaper than having to get the entire ignition and electrical system repaired should a DIY replacement go horribly wrong.
WANT TO LEARN MORE?
MTA Queensland’s Vehicle Maintenance course is designed for those who are interested in gaining valuable information and learning good practices for everyday vehicle use. The result: a safer journey with fewer breakdowns and repairs. If you have ever wanted to learn how to carry out preventative maintenance, then this course is for you.
14 April 2020
Please note the information contained on this page is general in nature and does not take into account your specific needs or circumstances. You should consider whether the information is appropriate to your needs, and where appropriate, seek professional advice.