BMW cars equipped with the intelligent charging system may display a warning message stating Increased Battery Discharge or High Battery Discharge.
This problem often happens when you first start your BMW in the morning, especially during extremely cold weather. You may also get BMW increased battery discharge when stopped.
If you see this error message on your dashboard, some of the electronic consumers (such as heated seats, power features, blower fan, door locks, interior light, comfort access, etc.) may automatically be turned off to conserve the battery.
When you see this message remove any chargers or adapters from the cigarette outlet. Continue driving your BMW for at least 30 minutes to charge the battery.
If the problem remains the next step would be to verify that the battery is in good condition and holds a proper charge. Perform a charging system test and if need be manually charge the battery by connecting a 12-volt battery smart trickle charger at the jump terminals.
Don't worry if several items stop working including windows, folding mirrors, seats, sunroof etc. It doesn't mean there is something wrong with these systems. Your BMW is trying to conserve energy to allow the car to charge the main battery. Normal operation should return once the battery is charged.
The error message may vary between BMW models. Here are some errors we often see.
Verify that the error message remains. Go to Vehicle Status check on your iDrive / Navigation screen.
Go to Main Menu - Vehicle Information -Vehicle Status - Check Control - Increased Battery Discharge.
Increased battery discharge can be caused by several issues some of the most common being an old battery, defective IBS sensor, or poor ground connection.
Stock BMW batteries typically last around 4 to 6 years. If your battery doesn't hold a charge, you can get the increased battery discharge warning at startup or while driving. If the battery is failing, you typically get several other warnings as well.
An easy check you can perform is to look at the low beam lights or the running lights (engine must be off, ignition on), and determine if they look dim. If they are slightly dim or the car struggles to start, the battery may be the culprit. It is not uncommon for a BMW battery to fail even at two years due to a bad cell.
Note that other possibilities include the battery getting drained overnight or the battery isn't getting charged properly. If your BMW keeps dying when parked make sure that the smart key is not too close to the car.
For example, if the car is parked in the garage and the key is too close, keeping the systems awake. At the early stages the car will start fine, but over time your BMW may struggle to start. If your battery is over 7 years old it is a wise investment to change it.
A faulty IBS sensor could be the culprit. IBS sensor is installed on the negative battery terminal. Learn more about BMW IBS sensor here.
A poor battery cable connection can also cause the "increased battery discharge" warning message. Check the battery terminals to make sure they are not loose. Especially if you are getting this error message after replacing the battery.
If the battery terminals are not loose, remove the battery terminals and clean them using a battery terminal brush. They can corrode triggering the increased battery discharge error message. Make sure to check and clean the IBS sensor cable as well connected to the negative battery cable.
Other possible issues include a defective alternator which is failing to charge the battery properly. Auto parts stores such as Advance Auto Parts can perform free charging system tests.
If you are using your BMW for short trips, you are not giving your battery time to get charged properly. This can result in reduced battery charging. If that is the case you may want to connect a trickle charger overnight to the battery or take your car on longer trips (at least 30 min drive) once a week.
You don't need to drive on the highway to allow the battery to charge, city driving works too. Keep electronic consumers to a minimum such as the stereo or heated seats. Keep the day running lights off. This will allow the battery to charge faster.
An electronic device or a high power charger plugged into the cigarette outlet may drain enough power to trigger this error message. Make sure that you unplug any phone chargers or GPS units from the 12-volt cigarette outlet. Don't forget to check the rear outlet if you have one.
During cold temperatures, batteries performance drops. On top of that, you are more likely to turn on several consumers such as heated seats, defrost, wipers etc. If you have an old car battery on your BMW there is a high chance you are going to get increased high battery discharge error.
First, make sure that you don't have devices plugged into the 12-volt outlets. For example unplug all phone chargers, GPS charging cable or any other device.
It is normal for the Increased Battery Discharge or High Battery Discharge warning in cold weather or morning when you may have several items turned on such as the heat, blower fan, rear defroster, heated seats, the radio, lights, maybe even that heated steering wheel.
If that is the case, check the age of the battery and replace if it is older than five years. If the battery was recently replaced or is relatively new, make sure the BMW battery is coded properly.
Fully charge the battery either by using a battery charger or driving your BMW for at least 30 minutes. If the error message comes up again it is time to perform further troubleshooting.
The second test you can perform is to measure the battery voltage. For this, you will need a digital multimeter. Don't worry if you haven't used one before. They are very easy to use.
Connect the multimeter to the battery positive terminal under the hood while the engine is off. The battery needs to provide at least 12 volts. Turn on the ignition, and the battery voltage should remain over 12 volts. Start the car and recheck the voltage. It should be between 13 and 14.5 volts. If the battery doesn't maintain over 12 volts it may need to be replaced.
If the battery tests good, the next step is to read the codes from the DME module and perform a full system scan.
This is a simple procedure that you can perform yourself but requires a good BMW OBD2 scanner.
Pay attention to other modules that may have stored fault codes. It is possible that another module is malfunctioning and drawing too much current from the battery. For example, the stock amplifier could be drawing too much current.
EDC module can also draw excessive current. To verify, disconnect the EDC module which is known to fail and trigger Increased Battery Usage warning. The EDC module is located in the trunk. You should still be able to drive your BMW but can not change the stiffness mode if you disconnect the EDC module.
If that doesn't work, determine if you have connected any accessory directly to the battery negative terminal. Remove the connection from the terminal and use one of the ground points/bolts on the body.
Another thing to check is to verify that your BMW goes to sleep once it is parked. Once the BMW is parked and turned off, most systems stay powered for a few another 20 minutes. Then the majority of the systems will go to "sleep". You can allow the car to go to sleep and then check for an excessive current draw at the fuses. To do this you will need to leave doors or hood open so that you can access the fuse panel and allow the car to go to sleep.