What causes BMW increased battery discharge error? The error message appears on the iDrive screen and can be accompanied by other signs. They include instrument cluster flickers, service vehicle error appears, engine unexpectedly stops, electrical accessories turns off, etc.
The battery discharge warning can be caused by a bad battery, parasitic drain, corroded/loose battery terminal, faulty battery charging system, cold weather, etc. Therefore, you need to find the specific cause to fix the problem. Fortunately, there is something you can do yourself before taking your vehicle to an auto mechanic shop.
Read on for detailed information about the causes and how to fix a BMW increased battery discharge.
Table of Contents
- 1 What is Increased Battery Discharge in a BMW?
- 2 Is It Safe to Drive with the Increased Battery Discharge Popping Up?
- 3 Common Symptoms and Related Error Messages of Increased Battery Discharge
- 4 Increased Battery Discharge: Possible Causes and Fixes
- 5 What To Do When BMW Shows Increased Battery Discharge Message with a New Battery?
- 6 Conclusion
What is Increased Battery Discharge in a BMW?
Increased battery discharge is an error message that your BMW vehicle displays on the iDrive screen. It means the battery power falls below the recommended level. The battery may not provide enough power to start the engine next time. So, your first reaction should be to leave the engine running for a while to recharge it.
It is more prevalent in winter or cold weather when people tend to drive short distances and use many car accessories that draw more battery power. However, there are other causes, as we will learn later.
Is It Safe to Drive with the Increased Battery Discharge Popping Up?
Yes. It is advised to drive even longer for the battery to recharge. What usually causes this issue is short trips when you are using all car accessories such as AC, heated seats, etc. These power-hungry applications draw more current from the battery. So, driving longer will allow the battery to recharge.
However, driving with the BMW increased battery discharge message is not a good idea if it is not caused by running electrical accessories. If there is a fault in the battery charging system or a short circuit, it can leave you stranded. Therefore, the best action is to diagnose the vehicle to know the exact cause before driving on.
Common Symptoms and Related Error Messages of Increased Battery Discharge
The BMW battery discharge warning is associated with many symptoms, which include the following:
- Battery dashboard symbol or charge battery warning
- Vehicle on a lift warning light on the dashboard
- The engine fails to start.
- The engine unexpectedly shuts down while driving or at idle
- Some electrical accessories turn off or a general electrical malfunction.
- Battery discharges while the car is parked
- Flickering instrument cluster
The error message on the iDrive screen varies depending on the BMW model. It may be one of the following:
Battery charge very low
Start the engine immediately and recharge by driving for an extended period or using external charger. Functions requiring power supply, such as communication, entertainment, air conditioning.
Battery Discharging while stopped
Turn off unnecessary electrical consumers. Reset date and time if required. In case of a repeat occurrence, have the system checked by a mechanic.
Battery discharging while stopped
Electrical devices were temporarily switched off.
Increased battery discharge when stationary
Electrical consumers were temporarily switched off.
Increased Battery Discharge: Possible Causes and Fixes
How do you fix a BMW battery discharge error? That’s only possible if you know the cause and follow the procedure. So, let’s break it down.
Electrical Devices/Accessories are On
Electrical accessories such as heated seats, AC, radio, or phone chargers inserted in the cigarette lighter socket can impact your battery. If they draw more current than the battery charging system can generate, the battery voltage will drop. That will definitely cause the onboard computer to display an increased battery discharge warning message on the iDrive screen.
If the battery discharge warning error appears when driving, turn off all non-essential accessories. You can even sing to yourself instead of playing the radio if that can help. The warning message should disappear if electrical consumers were the cause. If that doesn’t happen, look for other reasons.
Battery terminals get corroded over time. Evidence of corrosion is a white powdery substance coating them. This can significantly increase the electrical resistance that hinders the flow of electrical current. A battery monitoring system detects that as a low voltage and then sends a signal to the onboard computer.
Loose battery terminal connections can also disrupt the path of electrical current. As a result, the battery won’t charge, and intermittent power is transmitted to the electrical systems. It is the most common cause of a flickering instrument cluster.
Fixing the loose connection or corroded battery terminals is straightforward. You only need to unbolt the cables connected and then clean them. Once done, reconnect everything, ensuring that everything is tightly fixed.
Your stock BMW battery can last for about 4-6 years. Over time, the cells are so worn out that they can no longer hold sufficient electrical charge. If that is the case, you will get an increased battery discharge warning that disappears when you start the engine. Also, car accessories may shut down soon after stopping the engine because the battery has no power to keep them running.
Test the battery and replace it if it is too weak to hold more electrical charge needed by your car. Get a digital multimeter and proceed as follows:
Step 1: Stop the engine and open the hood to access the battery.
Step 2: Set the digital multimeter to about 20V DC range and connect the red probe to the positive battery terminal and the black probe to the negative battery terminal. The battery voltage should be 12.6V or more if it is okay. Any reading lower than 12V indicates it is fully discharged.
Step 3: Turn the ignition once without starting the engine to power the electrical accessories. Read the voltage and notice if there is a significant drop or not. If there is, the battery is weak.
Step 4: Start the engine and read the battery voltage once more. It should drop a little and then increase to around 14V. If the drop during starting is significant (below 10V), it indicates that the battery is weak.
Faulty IBS Sensor
An intelligent battery system (IBS) sensor monitors and measures battery performance. It is connected to the negative battery terminal. Despite its vital role, the IBS sensor can cause parasitic drain if faulty. It is the common cause of the BMW increased battery discharge while stopped. So, you should test and replace the IBS sensor if it is the culprit.
Conduct a visual inspection to check if the IBS sensor has a fault. Look for any signs of corrosion, cracks, loose connections, physical damage, and broken connector wires. Other electrical accessories connections bypassing the IBS sensor can also cause the problem.
The second testing method is using a BMW-recommended OBD2 scanner. You can buy or borrow one from a friend and proceed as follows:
Step 1: Locate the OBD2 port under the dashboard on the driver’s side and plug in the diagnostic scanner.
Step 2: Turn on the ignition without starting the engine and turn on the scanner to connect with the onboard diagnostic system.
Step 3: Select your BMW make and model, and then proceed to the control units.
Step 4: Select DME from the menu and choose read fault codes. The IBS sensor error codes are stored in the DME module. If there is a fault, the reading will be one or more of the following:
- Voltage fault
- 299B DME Intelligent Battery Sensor
- 002E8D DME: IBS signal transmission
People make short trips that do not give the battery enough time to recharge in cold weather. Also, many electrical consumers are in use. As a result, they draw more power from the battery, which is detected as increased discharging by the monitoring system.
Using fewer electrical accessories may be the first step you need to take to solve the problem, but the cold weather may force you to use heated seats and AC. So, what should you do next?
The best way to go about it is to use an external battery charger to recharge overnight. However, that’s only advised if there is no parasitic drain or a problem with the battery.
Parasitic current drains can affect your car even after installing a new battery. It is often caused by a short circuit in electrical systems. Thus, the solution is to identify the specific electrical circuit responsible for the parasitic drain and fix it. You can do that through a DIY approach or by calling your mechanic.
What To Do When BMW Shows Increased Battery Discharge Message with a New Battery?
If your BMW still shows an increased battery discharge warning message with a new battery, conduct a further diagnosis. First, ensure the battery is fully charged to eliminate it as a potential culprit. So, what is the problem? It includes a faulty ground strap, IBS sensor, alternator, corroded/loose battery terminal connections, or too many running electrical accessories.
Start by diagnosing your car for all these possible causes to find the culprit. The error message should disappear after you fix the problem.
The BMW increased battery discharge error message often appears during cold weather. However, it can also be due to other reasons. The common causes of this warning message include an old battery, faulty IBS sensor, many running electrical accessories, and a short circuit. It is usually an easy-to-fix error. Just diagnose the car and fix the identified problem.