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Car Battery problems - Non-manufacturing faults

Sulphation of a car battery:

If a car battery is allowed to stand in a discharged state for an excessive amount of time, a chemical reaction takes place, which can permanently impair performance - this is sulphation. Sulphation can be seen as a fine white/grey coating on the plates. In most cases this signifies irreversible damage and the car battery will not be serviceable. This damage can occur either in storage or if the car battery is installed in a vehicle (or equipment) that is not used for a period of time, for example a tractor, motorcycle, or boat. Even a car or truck that is stored with the battery connected can still damage the battery in this way. This is because there is a permanent drain on the battery from the clock, alarm etc. As a result the level of charge in a car battery falls, and after a period of time sulphation will build up on the plates.

The sulphation (lead sulphate) hinders the chemical reaction between the acid (electrolyte) and the active mass (lead compound) in the plates and prevents the car battery from operating as normal. This is not a manufacturing fault.

Wear and Tear of a car battery:

During the charge and discharge cycle, material from the battery plates (active mass) is in motion, through the electrochemical reaction that produces electricity. Every time the car battery goes through a charge and discharge cycle, a small amount of the active mass is lost from the plates. Because the ultimate life of a car battery depends on so many factors, it is impossible to stipulate a minimum/maximum life expectancy. This process of normal ageing through the charge and discharge cycle will eventually cause the car battery to lose capacity, and it will come to the point where the battery can no longer start the vehicle/equipment. This is not a manufacturing fault.

A car battery only has a finite number of cycles (x) it can go through before it loses its capacity to perform. Vehicles with high usage such as taxi’s, minicabs, trucks, and buses will often subject the battery to its x number of cycles but over a much shorter time. As a result, batteries on these vehicles can display the above symptoms after 12-24 months. This is not a manufacturing fault.

Deep cycling a car battery:

As mentioned above, every time a car battery goes through a charge and discharge cycle a small amount of the material from the plates is lost. If a car battery is subjected to deep discharging (i.e. over 40%) and then rapid charging, this process is accelerated. Additionally, if during the recharge the car battery is not adequately compensated for the discharge cycle, the battery will quickly exhibit loss of performance. Even after recharging the voltage will be low (under 12.4v) but the cells will generally give even readings. This is not a manufacturing fault.

Overcharging a car battery:

If the regulator is not set properly, then the car battery can be subjected to an excessive charge. If left unchecked the battery will overheat and will start to evaporate the electrolyte. The overcharging will cause the accelerated break up of the active mass on the plates and the car battery will lose performance. This is generally obvious from the examination of the battery - the acid levels will be very low, and quite often a black coating will be visible on the filler caps. This is not a manufacturing fault.

Physical damage to a car battery:

If the car battery is fitted incorrectly, if the connector leads are hammered onto the terminals, or if the leads are not properly fastened, the car battery will have obvious damage to the casing or the terminals. This is not a manufacturing fault.

Incorrect application of a car battery:

The car batteries recommended by Car Battery Shop are those equal to or above the original equipment specification. Fitting a smaller or less powerful car battery will result in a shorter service life and earlier failure, which will generally manifest itself as deep cycling/premature wear and tear. This is not a manufacturing fault.

Car battery problems - Manufacturing faults

Due to the high demands of the OEM market, and taking into account the technical and manufacturing standards adhered to by Car Battery Shop, the rate of genuine manufacturing faults is negligible.

Car battery short circuit/dead cell:

Typically seen in a car battery with a short (under 12 months) service life. One cell will show a dramatically lower specific gravity (SG) reading than the others. The affected cell will boil visibly under a high rate discharge test. In some cases it may also be visible as a sulphated cell (see above). The remaining cells will show a good SG reading of 1.26 or over.

Internal Break in a car battery: The car battery will have good SG readings but no voltage.


Provided the right car battery, in the right condition is used for the right application, the number of battery problems encountered will be minimum. All car batteries have a finite life span, which is governed by the conditions under which the battery operates. Car battery failures caused by sulphation, wear and tear, or deep cycling are not manufacturing faults and are not covered by a guarantee.

It is important to remember that under normal operating conditions, a car battery cannot become discharged on its own. The reason for this discharge is normally attributable to:-

  • Malfunctioning alternator, regulator, or starter motor
  • Slipping fan belt
  • Electrical fault
  • Excessive use of electrical consumers - car phones, air conditioning etc
  • Long standing time without recharge
  • Boot light/glove box malfunction
  • Vehicle lights being left on

If a car battery is consistently used/left in a discharged condition, it will eventually reach a condition where even a prolonged recharge will not return to its original condition. This is classified as deep discharge/undercharging and is not a manufacturing fault.

If a car battery is continuously deeply discharged by, for example, stop start motoring and heavy use of the car phone, air conditioning etc, and is then not adequately recharged, it will lose its performance relatively quickly. This is called deep cycling/wear and tear and is not a manufacturing fault.

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