Audi Q5 Alarm Failure Points to Hidden Battery Issues

I had almost the exact same issue with my Audi Q7 2018 gasoline model. Having some experience with car batteries and electrical systems, I first thought it was just a regular car battery problem. The alarm system shutdown was the first sign something was wrong. After the auxiliary battery started acting up, error messages kept popping up out of nowhere. A complete battery check revealed the original battery was severely degraded despite showing normal battery signals on the dash. The workshop performed: Full system diagnosis, Battery capacity test, Alarm system component check, Replacement of main battery, System reset and recalibration Total cost was 330 Euro and it solved all issues. The car has been running perfectly for 8 months now. What specific error messages are you seeing? Knowing the exact codes would help determine if your case matches mine. Also, has your battery ever been replaced since 2020? This information would help provide more targeted advice about your situation. A proper battery check is crucial as dashboard signals dont always show the real battery condition, especially with modern cars complex electrical systems.

Had my latest service just 2 weeks ago at 49145 KM and can confirm your diagnosis matches what I am experiencing. The error messages vary but mostly show auxiliary battery and alarm system warnings. The electrical issue started suddenly last week with unusual warning lights. After reading your response, I suspect my original battery may be the root cause, especially since it has never been replaced. This makes sense given the similar symptoms and the fact these electrical systems are interconnected. A proper battery check sounds like the logical next step before investing in a full system repair. The 330 Euro cost reference is helpful for budgeting. Will schedule a diagnostic focusing on the battery problem and alarm system components. Thank you for the detailed breakdown of the repair process your workshop followed. It gives me a clear picture of what to expect.

The battery replacement solved all those issues in my case, and it seems you are on the right track suspecting the original battery. These Audi models share very similar electrical architectures, so the symptoms typically manifest the same way. The fact that your warning lights started suddenly after the recent service is actually a common pattern. The system diagnosis during service can sometimes trigger latent battery alarm issues that were building up but not yet visible. One thing to note from my experience: make sure they check both the main and auxiliary batteries during diagnosis. My workshop initially only tested the main battery, but the electrical issue was actually linked to both systems working together. When the auxiliary battery starts failing, it can trigger those unusual alarm system warnings you mentioned. The 330 Euro I paid included both batteries check and replacement of the main unit. If your auxiliary battery also needs replacement, costs might be slightly higher. The good news is that once properly fixed, these electrical issues rarely return. Keep us posted about what the workshop finds. Would be interesting to see if the diagnosis confirms the same root cause.

Thanks for explaining your experience with the Q7. After seeing all these responses, I am definitely going with a full battery check focusing on both main and auxiliary systems. You are right about checking both, makes no sense to only test one when they work together. Since posting my initial question, more error messages appeared showing battery alarm warnings, which matches the pattern you described. The timing after the recent service also fits what you mentioned about latent issues becoming visible after diagnostics. Will schedule the workshop visit next week and ask them to: Run complete battery diagnostics, Test both main and auxiliary batteries, Check alarm system components, Look for any service-related triggers The cost estimate helps with planning. Even if it goes above 330 Euro due to needing both batteries replaced, it seems worth it to fix these electrical issues properly the first time. Will post an update once I have the workshop results. Thanks again for helping me understand what to expect from the repair process.