Dead Audi Q5 Battery Causing Multiple Warning Lights

When my 2015 Audi Q7 3.0 TDI showed similar symptoms, it turned out to be more than just a simple battery drain. The battery sensor was defective, causing incorrect readings to the electrical system. The symptoms matched exactly, error messages, dim lights, and difficult starts in the morning. A faulty battery sensor can trick the system into thinking the battery is fine when its actually failing. The real problem became obvious when testing revealed the alternator wasnt properly charging the battery due to false sensor readings. The repair required: Complete electrical system diagnostic, Replacement of the battery sensor, Installation of a new battery due to damage from improper charging, Recalibration of the electrical system This was a serious issue that needed immediate attention, as continued driving risked damaging other electrical components. Low battery voltage can affect multiple systems including the start-stop function and regenerative braking. Key signs to watch for: Multiple electrical system warnings, Battery warning light, Inconsistent start behavior, Dimming lights during idle Have the battery terminals checked first, but be prepared that the issue might require deeper diagnosis of the electrical system. These symptoms often indicate more than just a discharged battery.

Thanks for sharing that experience. I had almost identical issues with my Audi Q5 last winter. The battery charging system was giving me all sorts of headaches with similar warning lights and startup problems. I found out it wasnt just the discharged battery but also corrosion on the battery terminals that was causing poor connections. The low battery voltage was affecting multiple systems. Just curious, do you remember roughly what the total repair cost was for your situation? Also, has everything been working properly since the fix? No lingering electrical system issues? My repairs were quite involved but it would be helpful to compare costs since these problems seem common in these models.

Thanks for asking about the follow-up. Since having the battery sensor replaced for 315 Euro, the electrical system has been working flawlessly. The mechanic found that the faulty sensor was the root cause of the heavy battery discharge, explaining all those frustrating symptoms we both experienced. The repair completely resolved the low battery warnings and irregular startup issues. No more dimming lights or electrical system warnings in over 6 months of driving. The new sensor ensures proper charging levels, preventing any battery drain problems that could damage other components. Interesting that you mentioned terminal corrosion, it shows how multiple issues can create similar symptoms. While the final cost can vary based on what exactly needs fixing, addressing a discharged battery problem early definitely helps avoid more expensive electrical system repairs down the line. The 315 Euro I paid seems reasonable compared to potential damage from running with a failing battery sensor. Most importantly, the car runs perfectly now with no lingering electrical issues.

Thanks for the input. After reading about similar experiences, I took my Q5 to a different mechanic last week. The total repair came to 280 Euro, which included cleaning the battery terminals, replacing the battery sensor, and installing a new battery. The mechanic was thorough and showed me how the old sensor was giving false readings, leading to the battery drain issues. They also found some corrosion affecting the connections. Once everything was cleaned and replaced, the car fired up instantly. Its been running great for the past week, no more error messages or dimming lights. All the electrical systems are working properly now. Really glad I caught this before it caused damage to other components. The repair cost was worth it for the peace of mind. Much better experience with this mechanic who took the time to explain the actual problems instead of just trying quick fixes.