Publisher Summary This chapter briefs up on taper charging of lead—acid motive batteries. Most chargers are designed so that, as the charging process progresses and the battery voltage rises during charge, the output current of the charger reduces. This charging characteristic is known as a 'taper' and is described by referring to the current obtained near the beginning and near the end of a typical charge. There are two basic types of charger fully self-compensating chargers and pre-programmed chargers. Fully self-compensating chargers are becoming increasingly popular as they require no supervision and bring a greater flexibility to the battery charging operation. In pre-programmed chargers when 10 h or more recharge time is available, a single-taper charger is used. This type of charger incorporates a voltage-sensing device set to operate when the battery voltage reaches 2.35 V/cell. When less than 10h recharge time is available, a two-step taper charger is used. The two-step taper charger has two separate taper characteristics in operation; the first at a high current rate, the second at a lower rate, brought in by a voltage sensitive relay, which at the same time starts a timing device. In addition, the chapter also provides the principles of operation of the spegel charger. This charger operates on the well proven principle of continuously monitoring the on-charge battery voltage and terminating the charge only when the stabilized conditions occurring at the top of charge are detected. The charge duration is therefore totally dictated by the battery and, in practice, vary considerably depending on actual requirements.