Conventional Charging

Fig 1: Identifying Conventional Charging

Courtesy of VOLVO CARS CORPORATION

For optimum battery charging, the output voltage from the alternator is calculated from the battery's calculated temperature. The temperature is obtained from the battery monitoring sensor.

Depending on the demand from the Engine control module (ECM), the Alternator control module (ACM) (charge regulator) regulates the output voltage according to the image above. With traditional conventional charging, the battery is always charged to a SoC level of 100%.

For the brake energy regeneration function, battery charging occurs in the conventional way until the battery has reached a SoC level of 80 %.

Reconditioning battery

Performed at least 3 times per year (at least every 120 days) with the purpose of preventing the battery from sulfating permanently. On this occasion, the battery is fully charged in a few hours. Charging can occur during several operating cycles.

Brake energy regeneration

Depending on which type of power consumers are active, control of the alternator occurs in different ways.

Brake energy regeneration, slow

Voltage sensitive consumers are activated. This refers to consumers that are sensitive to voltage differences where voltage changes can be noticed by the driver. The voltage changes slowly as brake energy regeneration is activated so that the change is not noticeable. Applies to consumers such as headlamps, fog lamps, fan motor and windscreen wipers.

Brake energy regeneration, quick

No voltage or power sensitive consumers are activated. The voltage changes quickly or immediately during brake energy regeneration.

Brake energy regeneration, slowly without discharging

Voltage sensitive consumers are activated. This refers to consumers that are sensitive to voltage and power differences. Applies to consumers such as engine cooling fan motor, preheating elements, connected trailer and blower fan. When voltage and power sensitive consumers are activated, the voltage changes slowly and the alternator voltage is not permitted to be less than 13.2V. This is to prevent the available output from being too low.