Evaluate battery charge level, basic function

GF54.10-P-1000A

Evaluate battery charge level, basic function

04.06.2020

Model

all (CAR)

Overview

This document contains the following information:

 General

 Evaluate battery charge level

 12 V on-board electrical system battery

 48 V on-board electrical system battery (vehicles with 48 V technology)

 High-voltage battery (hybrid vehicles, electric vehicles)

General

The energy management evaluates the battery charge level. It uses this as a basis to actuate various functions to guarantee vehicle mobility and a stable supply to all electrical consumers.

Evaluate battery charge level

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

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

 Battery voltage

 Current flow from and to the battery

 Battery temperature

 Internal resistance of battery

 Battery capacity

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

12 V on-board electrical system battery

In conventional vehicles with wet or fleece batteries, the parameters that describe the charge level of the 12 V on-board electrical system battery are recorded by the battery sensor at the negative pole of the 12 V on-board electrical system battery.

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

Additional battery for ECO start/stop (hybrid vehicles with backup concept)

The energy management evaluates the charge level of the additional battery for ECO start/stop immediately after the engine is started. The additional battery for ECO start/stop is briefly loaded. The resultant voltage drop is used by the energy management to calculate the internal resistance of the auxiliary battery for ECO start/stop. If the combustion engine is switched off during this evaluation run, the result is then discarded. When the ECO start/stop function is active, the energy management detects the voltage of the additional battery ECO start/stop each time the engine is started.

 The assessment of the charge level for the additional battery for ECO start/stop can also be started using the diagnostic tester.

48 V on-board electrical system battery (vehicles with 48 V technology)

An electronics system is integrated into the 48 V on-board electrical system battery that continually records information about the battery condition and sends it to the energy management for the 48 V on-board electrical system.

The 48 V on-board electrical system battery is heated at low temperatures through the low-temperature circuit and cooled at high temperatures. This extends the service life and ensures an optimum storage capacity of the 48 V on-board electrical system battery.

High-voltage battery (hybrid vehicles, electric vehicles)

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

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

	Function schematics
	Evaluate high-voltage battery charge level, function schematic	Model 167 with code ME05 (Hybrid drive 85 kW-94 kW variant (incl. plug-in))Model 177, 247 with code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))Model 213 as of model year 2021 with code ME05 (Hybrid drive 85 kW-94 kW variant (incl. plug-in))Model 213 as of model year 2021 with code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))Model 293 with engine 780	PE47.70-P-2500-97A
	Evaluate charge level of 12 V on-board electrical system battery, function schematic	Model 118, 177, 247Model 167, 293Model 213, 238, 257, 290 as of model year 2021	PE54.10-P-2507-97A
	Evaluate charge level of 48 V on-board electrical system battery, function schematic	Model 167 with code B01 (48V technology)Model 213, 238, 257, 290 as of model year 2021 with code B01 (48V technology)	PE54.10-P-2508-97A
	Control units
	Battery management system control unit basic function	Model all (CAR) with code 63B (On-board xEV charging socket Combo2/Type2) Model all (CAR) with code 64B (On-board xEV charging socket Chademo/Type1) Model all (CAR) with code 65B (On-board xEV charging socket China Standard GB/T) Model all (CAR) with code 66B (On-board xEV charging socket Combo1/Type1)	GF47.70-P-9895A
	DC/DC converter control unit, basic function	Model all (CAR) with code B01 (48V technology)	GF54.10-P-9891A
	Basic function of signal acquisition and actuation module	Model 118, 177, 247	GF54.21-P-9895A
	Basic function of signal acquisition and actuation module at front	Model 167, 293 Model 213, 238, 257, 290 as of model year 2021	GF54.21-P-9896A
	Components
	High-voltage battery, basic function	Model all (CAR) with code 63B (On-board xEV charging socket Combo2/Type2) Model all (CAR) with code 64B (On-board xEV charging socket Chademo/Type1) Model all (CAR) with code 65B (On-board xEV charging socket China Standard GB/T) Model all (CAR) with code 66B (On-board xEV charging socket Combo1/Type1)	GF47.70-P-2000A
	Battery sensor, basic function	Model all (CAR) except code U98 (LITHIUM-IONEN-STARTERBATTERIE (LISB))	GF54.10-P-2009A
	On-board electrical system battery, basic function		GF54.10-P-2011A
	48 V on-board electrical system battery, basic function	Model all (CAR) with code B01 (48V technology)	GF54.10-P-2016A