A car starting battery is used to start the vehicle. It supplies power that turns the starter which in turn rolls the engine. It also serves as accessories battery.
There are other types of car batteries for other purposes like a hybrid car's high voltage or traction battery. In this article, we are referring to 12 volts starting battery.
First of all, batteries are meant to die after a satisfactory period of use. We want to highlight some other causes that can cause batteries to go bad on earlier than they should.
Things that can cause a car battery to die
This can happen when there is an electrical or mechanical fault that is preventing the car from starting immediately.
Accessories left on
When accessory like car radio is left on for a long time when the engine is not running, the battery will drain and this can affect the lifespan of the battery, especially if this happens repeatedly.
Bad charging system
A faulty charging system can be a faulty alternator, bad cable, bad voltage regulator. A charging system that is under charging or over charging the battery will kill it early.
Under sized battery
A battery that is undersized will be overworked during cranking and when accessory load is high. This can shorten its lifespan.
Undersized charging system
An alternator that is undersized in terms of current delivery capacity won't be able to deliver sufficient current that should charge the battery properly.
Wires that are old, have developed significant resistance, have bad joints would not allow enough current and voltage to reach the terminals of the battery, causing insufficient charging.
Poor battery quality
It is known that low quality or substandard batteries don't last.
Bad electrical connections (wire joints, grounds, battery terminals and so on) can cause high resistance at those points. This impedes current flow to the battery. A loose battery terminal will cause arcing and this can damege the battery.
Engine that has mechanical fault that prevents it from turning freely will drain a lot of current from the battery during attempts to start it. Repeated attempts can easily kill a battery.
A bad starter might require several start attempts of which most won't successfully start the engine. This can affect the lifespan of the battery.
Excessive electrical load
Electrical loads including electrical accessories and extra electrical accessories fitted into a car which the battery cannot handle in terms of capacity will cut short the lifespan of the battery.
Batteries are meant to be tightly secured into their position as excessive vibrations can damage them.
A short circuit either at battery terminals or any part of electrical circuit can potentially damage a battery. This is one of the reasons why battery fuse is important. Short circuit can cause battery fuse to blow on order to protect the battery and circuit that includes the load.
Wrong battery type
Using a battery that is not meant to be used in that car can damage it. There are different types of car batteries. Common ones are flooded lead acid and AGM batteries. A wrong type of battery can be a victim of improper charging which will shorten its lifespan.
It is well known that extreme weather conditions affect the life of batteries negatively. We are referring to both extreme hot and cold weathers.
This type of drain happens when the battery is being discharged by some loads or accessories when the car is at rest. Depending on the severity of the drain, a car battery can be killed immediately or gradually.
One killer of batteries is corrosion. Corrosion can be internal to the battery or it can be at the terminals of the battery.
Human errors like polarity swap during battery connection and short circuiting the terminals by mistake can damage a battery.