Three-Step Charging Process

Modern lead-acid batteries will last longer and charge faster if they are charged in a particular sequence known as a three-step charge. The Truecharge 10 implements the three-step charging process.

In the first step, known as the bulk charge, the Truecharge 10 delivers its rated current (10 A) until the battery voltage approaches its gassing voltage—typically around 14.4 volts. The bulk charge step restores about 75% of the battery's charge.

The gassing voltage is the voltage at which the electrolyte in the battery begins to break down into hydrogen and oxygen gases. Under normal circumstances, a battery should not be charged at a voltage above its gassing voltage since this will cause the battery to lose electrolyte and dry out over time. Therefore the Truecharge 10 transfers to the next step, known as the absorption charge.

During the absorption charge, the charging voltage is held constant near the gassing voltage and the charging current is steadily decreased. When the charging current has decreased to approximately one ampere, the battery is fully charged. At this point, the Truecharge 10 transfers to its final step, known as the float charge.

The float charge is a maintenance mode in which the Truecharge 10 output voltage is reduced to a lower level, typically about 13.5 volts, to maintain the battery's charge without losing electrolyte through gassing. Unlike many other chargers, the Truecharge 10 can be left connected to your battery indefinitely without risk of overcharging.

The voltage levels mentioned in the paragraphs above are dependent on the type of battery (sealed vs. flooded) and on the temperature of the battery. The Truecharge 10 is equipped with selector switches to allow you to set it for your battery type and temperature.

Charger Operating Sequence

The microprocessor in the Truecharge 10 is constantly checking to ensure that the charger is working properly.

Once AC power is connected to the Truecharge 10, the microprocessor begins by checking whether a battery is connected properly to the charger. The Truecharge 10 will only start charging if the following

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