Evaluate Battery Charge Level, Basic Function - GF54.10-D-1000A

Model All (Light transporter) 

Overview 

This document contains information on:

• General 
• Function 
  • 12 V on-board electrical system battery. 
  • High-voltage battery (electric vehicles). 

General 

In order to ensure the mobility of the vehicle and the stable supply of all electrical consumers, the energy management continuously evaluates the state of charge of the battery. Depending on this, it controls various functions.

Function 

The state of charge of the battery is the ratio of the current charge to the maximum storable charge.

The energy management calculates the state of charge of the battery based on the following values:

• Battery voltage
• Current flow from and to the battery
• Battery temperature
• Internal resistance of battery
• Battery capacity

If the state of charge is too low, the battery must be charged.

12 V on-board electrical system battery 

On vehicles with a conventional AGM battery, the parameters that describe the state of charge of the 12 V on-board electrical system battery are recorded by the battery sensor at the negative terminal of the 12 V on-board electrical system battery.

On vehicles with a lithium-ion battery, an electronic system is integrated in the 12 V on-board electrical system battery.

Vehicles with a 24 V on-board electrical system have two additional 12 V onboard electrical system batteries connected in series. These do not have a battery sensor.

High-voltage battery (electric vehicles) 

The state of charge of the high-voltage battery is monitored by the battery management system.

The high-voltage battery is heated at low temperatures and cooled at high temperatures. This extends the service life and ensures an optimum storage capacity of the high-voltage battery.

	Function schematics
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