61 20... Notes regarding the lithium ion battery: Notes
Introduction
The lithium ion battery is used for the first time beginning on 03/2014 in the M3 F8x.
The constantly increasing energy demand of modern vehicle electrical systems calls for ever more powerful battery solutions. A modern luxury-class vehicle has some 100 actuator motors that have to be fed with electrical current. Added to these are safety, environmental and comfort elements which are increasingly becoming standard features, such as e.g. Antilock Brake System (ABS), Dynamic Stability Control (DSC), electric steering assistance, MSA, air conditioning and navigation system. Current consumption is considerable even when the vehicle is not in use.
In addition, the subject of light construction has an especially high priority, especially in M vehicles. A low vehicle weight contributes significantly to the sporty driveability of a vehicle. Compensation of additional weight with technical measures is limited.
The lithium ion battery has the following advantages compared to a lead-acid or AGM battery:
- Light weight (approx. 50% of the AGM battery)
- Increased cycle stability, resulting in longer service life
- Higher current consumption, resulting in a higher state of charge and better availability of customer functions (e.g. automatic engine start-stop function)
- Increased power at temperatures of >0°C, resulting in higher vehicle system stability
Brief component description
Lithium ion batteries can be detected based on the following characteristics:
- LIN bus connection inside of the lid
- Notes on the label
- Large degassification connection in the lid
- In the lithium ion battery, INTEGRATED ELECTRONICS are used in place of the intelligent battery sensor on the negative terminal of the AGM battery. The integrated electronics have similar tasks.
- In addition, the lithium ion battery has an integrated electronic disconnect switch for protection.
- The lithium ion battery has a black housing just like the AGM battery.
- "Magic Eye" does not exist, either.
Notes for service technicians:
Attention!
It is necessary when handling the lithium ion battery to observe some particular points pertaining to battery replacement and charging!
Charge
Do not use rapid-charging programs!
Attention!
When charging the Li-ion battery, preset chargers must be used for this application.
Before charging a lithium ion battery: ADJUST THE CHARGING VOLTAGE OF EXISTING CHARGER ADAPTERS ONCE .
When using chargers preset for lead-acid or AGM batteries, a charging voltage is created that is too high for the lithium-ion battery.
In the event of excessive charging voltage, the Li-ion battery circuit breaker may open generating, among other things, a ccm message on the instrument cluster.
Do not exceed the maximum charging voltage of 14.0 V when charging a lithium ion battery. This applies not only to lithium ion batteries out of the vehicle but also charging by use of the jump start terminal point
The lithium ion battery should only be charged at a battery temperature of > 5°C. If charging below 5°C absolutely necessary, the maximum current of the charger must be adjusted according to the following table. The maximum permissible charging voltage is 14.0 V.
| Battery temperature | Maximum permissible duration of the charge current |
| 5°C to 60°C | 180A |
| 0°C to 5°C | 30A |
| -10°C to O°C | 20A |
| -15°C to - 10°C | 10A |
| -25°C to - 15°C | 6A |
Disconnect switch
The lithium ion battery has an internal disconnection switch that can disconnect the lithium ion battery to protect it. The voltage at the battery terminals cannot be measured when switched off. A CC message is generated on the instrument cluster.
This means that the lithium ion battery is not necessarily defective when the voltage can no longer be measured at the battery terminals.
If the electronic disconnect switch is activated, a diagnosis of the lithium ion battery is necessary using the diagnosis tester.
The following table outlines the response of the disconnect switch in fault situations:
| Fault situation | Condition for reactivation |
|---|---|
| Overvoltage | Overvoltage is no longer applied. Voltage at the battery terminals < 14 V |
| Under voltage (protection from total discharge) | Apply a voltage of > 10 V to the battery terminals for at least 20 s (e.g. using a charger) |
| Operation at high temperature | Battery temperature < 80°C |
| Short circuit | Apply a voltage of > 10 V to the battery terminals for at least 20 s (e.g. using a charger) |
A power pack, charger or second battery (e.g. jump-start) can be used if it is necessary to apply voltage at the battery terminals to reactivate the disconnect switch according to the table above.
When a charger is used, it must have a mode for completely discharged batteries or manual start of the charging procedure because the battery will otherwise not be detected and the charging procedure will not start.
Housing
Attention!
Risk of damage!
Do not open lithium ion batteries!
The screws on the lid and on the bottom of the lithium ion battery are not intended for service work and may not be unscrewed!
Do not open the lithium ion battery because it will not be possible to close it tightly again. Additionally, touching current carrying components may cause high short-circuit currents that will lead to the destruction of the lithium ion battery.
Disposal/transport
Before transporting the lithium ion battery , ASSESS ITS TRANSPORTABILITY .