To close the battery contactors, you must precharge the battery. Depending on the manufacturer and type, this is completed through the battery or the power electronics in the vehicle.

If the precharge is completed by the power electronics, the precharge must be done by the DC cycler. Use the DC_Cycler_Precharge.SEQ routine in the test station initialization for the battery tester to complete this.

Figure 23. Precharge Function


As shown in the previous image, terminals 30 and 15 and the DC cycler are activated. The BMS actual voltage is then read by the BMS and transferred to the DC cycler as the upper voltage limit. This is approached by a setpoint current of 0.1 A (precharged).

The battery contactors are closed by setting the BMS drive request.