The warranty does not covered faults that are not due to a manufacturing issue. Examples of non-manufacturing faults are described below.
Sulphation occurs when a battery is allowed to stand in a discharged state for an excessive amount of time. When a battery voltage drops below a certain level, a chemical reaction known as sulphation takes place. In most cases this voltage is at or below 12.06v. Sulphation is normally irreversible, and can permanently impair performance of the battery, causing reduced performance and premature failure. Sulphation can be seen as a fine white/grey coating on the plates.
This damage can be caused if a battery is stored for long periods without charging, or installed in applications that are not frequently used, i.e. tractors, boats and motorcycles. Vehicles are prone to discharging batteries as there is always a permanent drain form vehicle clock, alarms etc. Over time, sulphation will build up on the plates, and hinder the performance of the battery.
It is worth noting that under normal operating conditions a battery cannot become discharged on its own (unless left for a long period of self-discharge). The reason for this discharge is normally caused by one of the following; malfunctioning alternator, regulator, or starter motor, slipping fan belt, electrical fault, excessive use of electrical items such as heated seats, air conditioning etc, long standing time without recharge, boot light/glove box malfunction, vehicle lights being left on, etc./p>
As sulphation is easily avoided by simply keeping your battery charged, this is a non-manufacturing fault.
Wear and Tear, and Deep Cycling
When a battery is charged and discharged, material from the battery plates (active mass) is in motion, through the electromechanical reaction that produces electricity. Every time a battery goes through a charge-discharge cycle, a small amount of this active mass is lost from the plates. Due to so many factors impacting on the life of a battery, it is impossible to stipulate a minimum or maximum life expectancy.
Every battery has a finite number of cycles that it can go through before it loses its active mass, and in turn, its capacity. Vehicles with high usage, such as busses, taxis and trucks, will often put a battery through this finite number of cycles over a much shorter amount of time, causing a battery to show the above symptoms after only a couple of years. This is not a manufacturing fault.
When a battery is subject to a deep discharge, and/or a rapid rate of recharge, the above process is accelerated. A battery that is deep discharged regularly, or is often discharged blow 50% (12.1v) in the case of leisure batteries, will rapidly lose its active mass, and capacity. An example of this is the use of a leisure battery for running window cleaning water pumps. The loss of active mass, and therefore capacity due to over/excessive cycling is not a manufacturing fault.
If a battery is charged at an excessive voltage or current, it can overheat, and the electrolyte will start to evaporate. Overcharging will cause the active mass in the plates of the battery to rapidly breakup, and battery performance will be permanently affected, as will the cyclic life of the battery.
This is normally quite obvious to spot when examining the battery. During charging, there may be a pungent smell of rotting eggs. When off charge, the battery will have low levels of acid, and there may be a black coating on the filler caps (It is not possible to check the levels or maintenance free batteries). This is not a manufacturing fault.
Any physical damage that occurs to the battery terminals or casing due to improper fitment, if the battery is dropped, if any connectors are hammered on to the terminals, or if connectors are not properly fastened, the battery may fail rapidly. This is not a manufacturing fault.
Fitting a smaller or less powerful battery, or the incorrect type of battery for the application will result in shortened lifespan and premature failure. This is not a manufacturing fault.
Provided that the correct battery has been selected for the correct application or vehicle, instances of manufacturing faults will be minimum.