Audi S7 Battery Issues, Warning Signs and Solutions

I had a similar issue with my Audi S6 2018 and can share some experience having dealt with electrical problems before. The symptoms you describe match exactly what I experienced, especially the weak starts and dash error messages. After multiple attempts to diagnose the battery drain, my workshop identified a faulty battery sensor that was sending incorrect charge status readings to the car's computer. The repair involved: Complete electrical system diagnostic scan, Testing the vehicle battery and charging system, Replacing the battery monitoring sensor, Recalibrating the new sensor to the vehicle systems Total cost came to 315 Euro including parts and labor. Since the fix, the electrical issues completely disappeared and the battery maintains proper charge. To help provide more specific advice for your case, could you share: How old is your current battery? Are you noticing the battery drain happening overnight or while driving? Have you had any recent electrical accessories installed? Does the battery warning light stay on constantly or flicker? These details would help determine if your issue matches what I encountered or if there might be other factors affecting your car battery performance.

Latest service was at 186000 KM, just 2 weeks ago. Thanks for the detailed feedback on the discharged battery situation. After your questions, I can add that this is still the original battery from 2016. The battery failure symptoms occur mainly overnight, the car shows full electrical system failure messages after sitting for 8-12 hours. No aftermarket accessories installed. The red battery warning light comes on consistently during cold starts and stays lit until the engine warms up. Your experience with the battery sensor sounds very similar to my case. The car battery diagnostics would be a good starting point. Will get it checked since the symptoms match almost exactly what you described with the faulty sensor.

Based on the mileage and age details you shared, I can definitely help narrow down the issue with your discharged battery situation. My S6 actually showed identical symptoms with the original battery, which also lasted about 6 years before failing. The constant battery warning light during cold starts was the key indicator that prompted me to take action. After dealing with my battery sensor issue, I learned that the factory-installed car battery typically lasts 5-7 years in these models. The original battery terminals can also develop corrosion over time, affecting the electrical system connection quality. From your description, you might be dealing with both an aging battery and potentially the sensor issue I encountered. Since your battery is now 7 years old, I would recommend: 1. Testing the car battery first, its likely at end of life 2. Checking for corrosion on battery terminals 3. Having the battery sensor tested as a secondary measure A new battery with sensor replacement cost me around 450 Euro total. If you only need the battery, expect to pay about 250 Euro. The investment was worth it as it resolved all electrical system warnings and starting issues completely.

Your car has really helped pinpoint the battery drain issue. The original battery from 2016 is definitely the prime suspect, and the symptom pattern during cold starts matches classic battery failure signs. Interesting that both our vehicles showed similar warning behaviors with the battery sensor. The battery terminals will need inspection and I expect some corrosion given the age. Makes sense to start with a full battery test before jumping to sensor replacement, especially since my battery warning light behaves the exact same way during cold starts. Will schedule the diagnostic work and likely go for a complete battery replacement since mine is past the typical 5-7 year lifespan. The 450 Euro cost range sounds reasonable for peace of mind and preventing any potential starting problems as winter approaches. Thanks for confirming this is a known issue, helps validate that I'm on the right track with the diagnosis. Looking forward to getting the same reliable cold starts you mentioned after your repair. Will update once I get the work done.