Electrics/Electronics

Vehicle Electrical System - Power Management Battery










The AGM battery is a maintenance-free, sealed battery.
This battery must not be opened, if the battery is opened it must be replaced.

When replacing a battery in the gateway control unit, enter both numbers using the following path:
- Gateway/Maintenance, Repair/Battery replacement.
- The battery size and manufacturer must also be entered when replacing the battery.

Replacement Information
- Battery terminals do not need to be greased.
- The battery terminal clamps must only be attached by hand without using excessive force (such as a hammer) to prevent damage to the battery.
- The tightening torque for the battery clamps is: 6 Nm ± 0.5 Nm (4.5 ftlb. ± 0.5 ftlb.).
- The battery open-circuit voltage should not fall below 12.5 V.

NOTES:
- Connect the battery charger and jump leads directly in the engine compartment.
- If the charger or jumper leads are connected at the battery, the battery sensor may become damaged. In addition, incorrect information (battery charging directly at the battery sensor) is forwarded to the gateway.

Battery Technology - Absorbed Glass Mat (AGM)







The AGM batteries are completely maintenance-free throughout its entire service life thanks to a special separator. A valve seals the cell. Gases that are generated are removed electrochemically at the counter electrode. This means that very little fluid is lost and refilling with water is no longer necessary or possible. If the battery is opened, it must be replaced. (Refer to the workshop data when replacing batteries.)

Battery Sensor

The battery sensor is located on the negative terminal of the battery, it is part of the energy management system (battery management). The battery sensor is connected between the negative terminal of the battery and the ground cable.







IMPORTANT: Always connect the charging cable/jump leads directly in the engine compartment as otherwise the battery sensor could be damaged.

Tasks:
- Measures battery voltage
- Measures battery power
- Measures the temperature at the negative terminal

Using algorithms, the battery sensor (slave) calculates the current battery condition from these values in the ECU and communicates this value to the gateway (master).







The battery sensor has an electrical connection to the battery terminal and the ground strap of the vehicle. There is a further connection to the battery's positive terminal to register voltage and to the gateway via a LIN connection. The entire electric current of all components (including the battery sensor) flows through the shunt to the negative

terminal. The direction of charge of the energy delivered by the generator is routed to the positive terminal. This means that a charging current or discharging current (closed-circuit current) can be determined by the evaluation electronics.







The battery sensor is a module that monitors and diagnoses battery activity, it is a LIN slave module in a LIN network that communicates with the gateway.

It is connected directly to the negative terminal:
- Operating temperature of -40 °F. to 221 °F. (-40 °C. to 105 °C.)
- Service life of at least 15 years
- Battery voltage measurement range of 6 to 16.5V
- Resistance between battery terminal and ground strap max. 300 microOhm
- ECU contains the NTC for temperature sensing

Power Distributor