Understand Common Causes of Car Battery Failure

It’s quarter past nine. You’re already fifteen minutes late to work! “Well, at least I have my own vehicle. I will manage!” or so you think. You hurriedly get into your car, turn the key for ignition but it won’t start. Ritually, you try a couple more times and thankfully it does. Without further thought, you speedily drive away!  After only ten minutes of the drive, your car stops suddenly and just won’t start!  “Ah! This stubborn as a mule of a battery!” You finally give up. Forget about getting late, you’re left stranded and wondering if you’ll even make it to work that day! But, what could be the reason behind this battery issue?

How Does a Car Battery Work?

Before coming to the causes, let’s find out how car batteries function. In purely technical terms, “a battery is a device that translates chemical energy into electricity.” All batteries are composed of cells that store up chemical energy which can be converted to electricity on demand.

Now, most car batteries function on lead-acid chemical reactions and fall into the “SLI” category – Starting, Lighting and Ignition. What this means is such batteries deliver short bursts of energy that powers your devices, in this case, the car’s engine. Once the battery has ignited your car’s engine, further power is supplied by the alternator. An interesting feature of such batteries is that their chemical reaction is completely reversible; the reason why you can recharge them for as long as they are alive! Which also means that they can indeed die and once their time comes, die they will! But, premature battery failure is not an uncommon phenomenon. So, what are the most common causes of car battery failure? Let’s find out. 

Common Causes of Car Battery Failure

Human Negligence

Though causes that are beyond human control (natural causes) are also responsible for car battery failure, more often than not, it is human negligence that is the key contributor. But how? Well, firstly (and this is the most common reason), leaving interior lights, radio, and other infotainment systems on even when the engine is not in the active mode leads to drainage of your car battery’s power and may eventually cause premature death. And secondly, accidentally leaving car doors even slightly open can cause the interior lights or the dashboard lights to be turned on. If this persists for extended periods, it will lead to total battery drainage and also shorten the life of the battery. 

Parasitic Drains

An abnormal and continuous discharge of power that takes place even after the engine is turned off is known as a parasitic drain. It is self-evident that a parasitic drain will lead to battery failure eventually. Signs of parasitic drains include glove box or trunk lights that remain on when they shouldn’t. 

Defective Relay Switch

A relay is designed to complete the electrical circuit. By virtue of this, it is responsible for allowing the passage of electricity. A faulty relay switch could lead to repeated battery drainage – If the relay switch is stuck in the ‘on’ position, it will cause electricity to flow even when the engine is in a dormant state. This will not only wreak havoc on the car’s battery but will also damage the part that has the stuck relay. 

Extremes of Temperatures

Both sweltering heat and biting cold weather conditions have their own adverse effects on a car’s battery life. Where on one hand, extremely high temperatures can lead to evaporation of battery fluid, corrosion of the battery’s internal lead plates, and even malfunctioning of the charging system; on the other hand, temperatures too low are often responsible for reduced battery capacity and recharge rate and increased battery pressure due to solidification of engine oil. 

Increase in Internal Resistance

Measured in milliohms, internal resistance is the gatekeeper to a battery and the simple formula is – The lower the internal resistance, the lesser the constriction encountered by the battery in delivering the required power. In simpler terms, a battery with low internal resistance will deliver high power on demand whereas high internal resistance leads to heating up of the battery and low voltage, thereby lowering the runtime. Though sulfation and grid corrosion are the frequent reasons for increased internal resistance in lead-acid batteries; extremely cold weather conditions are also responsible for a rise in internal resistance.  

Too Many Short Drives

Yes, making excessive short trips are also one of the many reasons for car battery failure but it alone is not responsible. The time the vehicle has been left idle in between those short trips must also be taken into consideration. Meaning, if your car is frequently left unused for, say, several days and then is used for only making trips that are under 20 minutes, your car battery’s life will be cut short. 

End of a Battery’s Life Cycle

Just as we humans reach the sunset of our lives and need to say goodbye one day, car batteries will also not last forever. The reason your car battery has died could simply be attributed to ageing. Normally batteries have a lifespan of two to five years. Hence, be sure to check your car battery’s age and whether it needs to be replaced.

For world-class car battery installation and replacement services, contact AIS Car Fit Experts! Our highly trained professionals will cover all your car battery needs, be it your home, office or even on the road! You can even order car battery online and spare yourself the hassle of having to physically purchase it. Book an appointment with us today!


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