Notes regarding the lithium ion battery
Introduction
Lithium ion batteries will be used for the first time from 03/2014 in M3 F8x.
The constantly increasing energy demand of modern vehicle electrical systems calls for ever more powerful battery solutions. In a modern upper class vehicle, there are already around 100 servomotors that have to be powered electrically. In addition, there are safety, environmental and comfort elements that are increasingly becoming the standard, such as: Antilock Braking System (ABS), Dynamic Stability Control (DSC), electric steering support, Auto Start/Stop function (MSA), air conditioning system and navigation system. Power consumption is considerable even when the vehicle is not in use.
In particular, in M-vehicles, the subject of lightweight construction is also very important. Low vehicle weight makes a significant contribution to the sporty handling of a vehicle. Technical measures can only compensate for additional weight to a limited extent.
The lithiumion battery has the following advantages when compared to a lead-acid or AGM battery:
- Low weight (approx. 50% of the AGM battery)
- Higher cycle stability, thus longer service life
- Higher power consumption, resulting in a higher state of charge and better availability of customer functions (e.g. Auto Start/Stop function)
- Higher power at temperatures > 0°C, resulting in higher electrical system stability
Brief component description
The lithiumion battery can be recognized via the following features:
- LIN bus connection in the lid
- Notes on the label
- Large degassing connection in the lid
- Instead of the IBS at the negative terminal of the AGM battery, an integrated electronics is used in the lithium-ion battery to perform similar tasks.
- In addition, to protect the lithium-ion battery, a circuit breaker is integrated.
- Like the AGM battery, lithium-ion batteries have a black housing.
- "Magic Eye" is also not present.
Notes for service
Attention!
When handling the lithium-ion battery, a number of points regarding battery replacement and charging must be taken into consideration .
Charging
Do not use rapid-charging programs!
Attention!
For this application, preset battery chargers must be used to charge the lithium-ion battery.
Before charging a lithium-ion battery, adjust the CHARGING PARAMETERS of existing battery chargers once.
When using pre-set battery chargers for lead-acid or AGM batteries, a charging voltage that is too high for the lithium-ion battery will be applied.
If the charging voltage is too high, the circuit breaker of the lithium-ion battery can open, which among other things generates a CCM message in the KOMBI.
When charging lithium-ion batteries, the maximum charging voltage of 14.0 V . must not be exceeded. This applies to a removed lithium-ion battery and to charging via the jump start terminal.
The lithium-ion battery should only be charged at battery temperature > 5°C . If charging below 5°C is absolutely necessary. the maximum current of the charging device must be adjusted according to the following table. The charging voltage may not exceed 14.0 V.
| Battery temperature | maximum permitted continuous charging current |
|---|---|
| 5°C to 60°C | 180 A |
| 0°C to 5°C | 30 A |
| -10°C to 0°C | 20 A |
| -15°C to -10°C | 10 A |
| -25°C to -15°C | 6 A |
Disconnect switch
There is a circuit breaker in the lithium-ion battery that can switch-off the lithium-ion battery for protection. The voltage at the battery terminals cannot be measured when switched off. A Check Control message is generated in the KOMBI.
This means that the lithium-ion battery is not necessarily faulty if voltage can no longer be measured at the battery terminals.
If the circuit breaker is triggered, a diagnosis of the lithium-ion battery with the diagnostic tester is necessary .
The following table describes the behavior of the circuit breaker in faulty situations:
| Fault situation | Condition for reactivation |
|---|---|
| Overvoltage | Overvoltage is no longer applied. Voltage at the battery terminals <14 V |
| Undervoltage (protection from total discharge) | Apply 10.0 V < voltage = <14.0 V across the battery terminals for at least 20 s (e.g. using a battery charger) |
| Operation at high temperature | Battery temperature < 80°C |
| Short circuit | Apply a voltage > 10 V across the battery terminals for at least 20 s (e.g. using a battery charger) |
In order to reactivate the circuit breaker according to the above table, if application of a voltage at the battery terminals is necessary, this can take place via a power pack, battery charger or a second battery (e.g. jump-start).
When using a battery charger, it must have a mode for totally discharged battery or manual start of the charging process, otherwise the battery will not be recognized and the charging process will not be started.
Housing
Attention!
Risk of damage!
Do not open lithium-ion battery!
Screws on the lid and bottom of the lithium-ion battery are not intended for servicing and must not be released!
The lithium-ion battery must not be opened as it can no longer be tightly sealed. In addition, high short-circuit currents can occur when live components are touched, which can destroy the lithium-ion battery.
Disposal/transport
Before transport of the lithium-ion battery , ASSESSMENT OF THE TRANSPORTABILITY OF LITHIUM-ION STARTER/AUXILIARY BATTERIES IN SERVICE WORKSHOPS !