Evaluate Battery Charge Level, Basic Function - GF54.10-P-1000A
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)
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 the 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 reference the internal resistance of the additional 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)
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 charge level of 12 V on-board electrical system battery, function schematic | Model 167, 177 | 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) | PE54.10-P-2508-97A | |
| Control units | |||
| DC/DC converter control unit, basic function | Model all (CAR) with code B01 (48V technology) Energy management for 48 V on-board electrical system | GF54.10-P-9891A | |
| Powertrain control unit, basic function | Model all (CAR) with code ME05 (HYBRID DRIVE 80KW VARIANT (INCLUDING PLUGIN)) Model all (CAR) with code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN)) Energy management for high-voltage on-board electrical system |
GF54.21-P-9894A | |
| Central controller unit, basic function | Model 177 Energy management for 12 V on-board electrical system | GF54.21-P-9895A | |
| Front central controller unit basic function | Model 167 Energy management for 12 V on-board electrical system | GF54.21-P-9896A | |
| Components | |||
| Battery sensor, basic function | Model all (CAR) except code U98 (LITHIUM-ION STARTER BATTERY (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 |