5 DIAGNOSTICS Batteries XF 95 series 1.2 SERVICE LIFE The service life of a battery is significantly shortened if it is used ‘cyclically’. This means that the batteries are used a lot without their being charged. For example when using a tail-lift, cab heater, microwave oven and a cooler box. This is why batteries in commercial vehicles and vehicles used for international transport often fail prematurely (within 1.5 years). 1 The battery must be charged whenever the voltage measured across the battery falls below 12.5 V. If the battery is not charged, the ‘sulphating’ process will begin. This is a chemical reaction in the battery that produces lead sulphate.
Lead sulphate adheres to the battery plates and can cause short-circuiting between the plates, reducing the capacity of the battery. However, most lead sulphate breaks down when the battery is recharged. If a battery is used (discharged) while it is not being charged by the alternator, short-circuiting between the battery plates will occur sooner. This reduces the capacity and consequently the service life of the battery. 1-4 200303