SERVICE PROBLEMS

Overcharge

Modern car charging systems allow only a small current to flow into the battery when it is fully charged. If there is a fault in the alternator, however, a much higher current will pass through the battery all the time that the car is running. This current will cause the battery to lose water rapidly, destroying the maintenance free characteristics of the battery, and will also reduce the life of the battery by damaging the positive grids. Adark brown/black color on the bottoms of the vent-plugs is the strong sign of overcharging. If the alternator has a voltage above about 14.4 V at normal temperatures, this is a sign that the charging system is faulty.

Deep cycle

Modern charging systems of vehicles keep the battery in a high state-of-charge. However, under abnormal conditions such as when parking the vehicle with headlights turned on, the battery will discharge. Furthermore, modern vehicles contain other consumers as well such as on-board computer, alarm, clock etc., and this will cause the battery to become discharged. Vehicle batteries are designed to be recharged a certain number of times. However, they are not suitable for applications where deep cycle appears.

Such applications require batteries of other types that have a special construction to enable them to be deep cycled on a continuing basis. Continual deep cycling of vehicle batteries will cause failure as the positive active material will gradually fall to the bottom of the battery, reducing the ability of the plates to store electricity. A large number of small black/brown particles in the electrolyte are a strong indication that the battery has been deep cycled.

Sulphation

Sulphation is a process that occurs whenever a battery is discharged. During the process of recharging, lead sulphate is changed back into active material. If a battery is left flat for a period of time, sulphation slowly changes its form and cannot be changed back into active material on charging. Therefore, the battery will not return to give its original performance.

Undercharge

Undercharge occurs if the battery is not receiving enough charge to return to a full state-of-charge. This will slowly cause sulphation and occurs if the car is being used only occasionally for short journeys, or for stop-start urban motoring. Undercharging also occurs when the alternator voltage is in the region of 13.6-13.8 V.

COLD CRANKING PERFORMANCE (AMPER)

The Cold Cranking Performance (CCA) measures the starting performance of the battery. In simple terms, the higher the CCA, the easier it will be to start the vehicle. This test is starting test according to the EN 50342 standard. Other manufacturers use different standard tests such as DIN, JIS, and SAE etc.

The test specifies that the battery at a temperature of -18°C will deliver a current equal to the Cold Cranking Amps for 10 seconds with the voltage staying above 7.5 volts.

Battery performance drops off quickly with the temperature, so this test is a good check of a battery's starting ability..

AMPER-HOUR CAPACITY AT 20 HOUR RATE (Ah)

The Ampere-Hour capacity measures the total amount of electricity stored in a battery.

An Ampere-Hour represents the amount of electricity when a current of 1 Ampere passes for 1 hour.

The Ampere-Hour Capacity varies with the rate at which the battery is discharged; the slower the discharge, the greater the amount of electricity that the battery will deliver.

The Ampere-Hour Capacity is the amount of electricity that a battery will deliver during 20 hours of operation, before the voltage drops below 10.5 V. For example, a 60 Ah battery will deliver a current of 3A for 20 hours.

RESERVE CAPACITY (MINUTES)

The Reserve Capacity is the amount of time in minutes that a battery at 25°C can deliver a current of 25 Amps until the voltage drops to 10.5V.

25 Amps represents a typical electrical load on a car under normal running conditions, so the Reserve Capacity gives an indication of the time that a vehicle with a normal electrical load will run with a broken alternator or fan-belt.

Obviously, the more electrical accessories you turn off, the further you can drive the car.

WATER CONSUMPTION

Ca-Sb batteries, compared to Sb-Sb batteries, have less water loss, which ranks them among 'maintenance free' batteries.