Nominal Battery Voltage

Nominal Battery Voltage

The default voltage for the generator is based on the temperature dependent maximum permitted battery voltage. The voltage range that can be set as the generator output voltage over the interface is between 13.5 volts and 15 volts. Since the battery temperature cannot be measured directly, the battery temperature is determined from a map using replacement values.

The battery temperature is calculated using the following available CAN signals:
- Coolant temperature.
- Outside temperature (filtered).
- Idle time of vehicle.
- Indicator light for auxiliary heating (coolant temperature rises when the auxiliary heating system is on).

Determining the Vehicle Electrical System Status

The status of the vehicle electrical system is mainly determined by comparing the determined voltage with a permitted lower voltage limit.

The values determined for:
- Battery voltage,
- DF signal (generator utilization),
- Information about active high current loads with a short "on" time are essentially used to determine the vehicle electrical system status.

The load switching states currently requested by the driver are also stored in the vehicle electrical system control unit.