Diagnosing a Failing Car Battery

Diagnosing a Failing Car Battery />


A good quality car battery is a fairly reliable piece of equipment. In most cases, if the battery is from a respected reseller or retailer, it will provide around 2-3 years of good service.

However, there are times when a battery may malfunction within the time frame specified above. Some warning signs do become apparent before the battery starts to play up.

We know that it is very important to be able to identify these signs. Let us shed some light on this topic and provide you with some of the possible indicators you might experience if your car battery is going bad.

The primary role of the battery is to provide current to the starter motor to crank the engine. One of the earliest warning signs of a bad battery is that it might “drag” when cranking the motor. This is a very recognizable phenomena BUT may not necessarily be the battery. If the engine does not swing easily as it did in the past, this could be an early warning sign. There can sometimes be confusion in this regard. If the engine is cranking but is failing to start, then the battery is performing its function, and this would indicate a fault elsewhere.

If the engine is dragging when cranking, the next step should be to check the voltage levels of the battery. A fully charged battery after being charged should read an OCV ( open circuit voltage ) of 12,6 to 12,75 volts . When cranking the car, should the voltage drop below 10.5 volts this would indicate a possible faulty battery. The assumption here is that the battery is in a fully charged state, either by means of frequent use of the car and charging via the vehicles alternator and / or supplementary charging by means of an intelligent battery charger such as the Ctek range.

The secondary role of the battery is to power the electronics of the car. This includes the interior lights, radio, headlights, etc. If any of these start to malfunction at the same time, then a bad battery may be the culprit instead of the electronic systems. Bearing in mind that the primary role of a vehicle’s alternator is to supply power to the electronics. The secondary role of a battery is to supply current to the electronics for short periods of time, either when the alternator has failed or when the vehicle has not been switched on.

Some other indicators with the engine switched off:

The hooter does not work

The radio randomly powers off.

The interior lights and headlights are dimmer than usual.

The interior fan does not function

If these symptoms present themselves then it may mean that you need to get your battery tested.

A misfunctioning alternator can also lead to a bad or dead battery.  The alternator is a component of the car that is responsible for charging the battery when the car is being driven.  As a result, any of the batteries' energy consumed from the starting process or by the electronics is quickly restored. However, when the alternator stops functioning properly, the battery no longer recharges and eventually discharges completely. The signs of a failing alternator are similar to the aforementioned signs of a bad battery.

If the red battery light on the dashboard comes on, this can imply a failing alternator which may eventually lead to a bad battery.

Since car batteries are SLI ( starting , lighting , ignition )  batteries, a complete discharge is harmful to them ( if discharged often ) and can cause permanent damage. The best way to get your battery diagnosed is to bring it to us at Battery Power Zone. Our qualified technicians can provide their expert opinion and give you a complete diagnosis of the situation you might be facing.

Some Modern smart chargers do come with testing functionalities as well. In fact, not only do they test and diagnose the battery, but they are also capable of suggesting a recommended course of action.

If you suspect that your battery is nor performing to specification, it is advisable to consult an expert. Our Battery Power Zone consultants will conduct a  FREE BATTERY AND CHARGING SYSTEM TEST. This will generally only take a few minutes. Better to be safe than sorry.