Many BMW owners call us about getting a “battery discharged” message on their dash. This is to alert you that your battery is getting low and the vehicle needs time to charge it before you shut the engine down again.

In cold weather (<10°C) people tend to drive short distances more often while also using more accessories (battery consumers). Heat, heated seats, heated steering wheels in addition to the stereo and headlights all can cause a significant draw on the battery. People will drive 5- 10 minutes to the grocery store and turn the car off, shop for ½ hour, and then return to the car starting the cycle all over again. Some of the newer cars even have a feature called engine Start/Stop designed to save gas when stopped at a light, this feature shuts the engine down but does not shut off any of the other consumers. When they get home and shut the car down it goes to sleep after about 10 minutes and the next time, they start it, the “increased battery discharge” message appears.

Driving short distances while using all of these vehicle accessories takes a great deal of power.  This causes the battery to discharge to a point where its current charge start is below the required minimum as sensed by the engine computer. The car may start the next time but unless it is driven for at least 45-60 minutes it may not have time to fully recover. This can cause numerous fault codes flooding the vehicle computer due to low voltage. Eventually the accessories will start to shut down in order to save the battery for the next start and to allow the alternator to catch up charging.

Fixing your battery discharge issues

The solution is to recognize these issues and adjust your driving habits to allow the battery time to recover such as:

• Reducing the number of short drives or allow the car to idle for an extended period of time during or after a short trip in cold weather;
• Install a C-Tek battery conditioning charger to plug the car in while it sits in sub zero weather and recharge when the car is not operating;
• Use as few accessory features as possible;
• Shut of the auto Start/Stop feature to preserve battery usage.

If none of these ideas work, then call our shop and we can diagnose potential alternate sources for the lower power message. It may be due to

• a battery that is older than 3-4 years old and has reduced capacity;
• a current drain from a module staying on in the car when it is shut down and supposed to have gone to sleep;
• a battery IBS unit that is faulty;
• a programming update to adjust computer sensitivity.

Atlantic Euro Cars has made significant investments in our diagnostic and programming abilities. We can help get your battery discharge warnings, or any other issues fixed right here in Saint John. don't hesitate to get in touch with any of your concerns.