Audi A5 Battery & Electrical System Warning Signs

Had similar battery malfunction issues with my 2018 Audi A4 diesel. The symptoms matched exactly, multiple warning lights, difficult starts, and unusual electrical glitches on the dashboard. After thorough diagnosis, it turned out the auxiliary battery was failing, which affected the entire car electronics system. The main battery was fine, but the auxiliary battery failure caused cascade problems with start-stop functionality and various electronic control units. The fix required: Complete auxiliary battery replacement, Reset of all electronic control modules, System diagnostic check, Recalibration of start-stop system This was a serious issue that needed immediate attention. Continuing to drive with a faulty auxiliary battery can damage other electronic components. The repair job took about 4 hours total. If your A5 shows these symptoms, get it checked soon. The auxiliary battery in these models typically needs replacement between 120000-150000km, so yours is in that range. Look for a shop with Audi-specific diagnostic equipment, its essential for properly resolving battery-related electronic issues in these models.

Thanks for the detailed response about the auxiliary battery issues. My situation sounds very similar. The multiple warning lights and power management problems were definitely concerning. I decided to take it to a specialist shop last week. Can you remember roughly what you paid for the full repair? My tech mentioned possible additional electronic module issues that might need addressing beyond just the battery replacement. Wondering if you experienced any other electrical gremlins after getting yours fixed? The engine start problems were really stressing me out, so I am hoping this solves it completely like in your case.

After getting the auxiliary battery malfunction fixed at the specialist shop, all my electrical issues cleared up completely. The total repair cost was 290 Euro for diagnosing and resolving the voltage drop problem. This included the new battery and necessary system resets. No electrical problems have returned since the repair. The car electronics are working perfectly now, no more warning lights, and the engine starts reliably every time. The battery replacement solved all the power management issues I was experiencing. The key was finding a shop that properly diagnosed the low voltage condition caused by the failing auxiliary battery. Once they addressed this root cause, the cascade of electrical symptoms disappeared. Its definitely worth getting it done right to prevent potential damage to other electronic components. No need to worry about additional module issues. In my case, once the new battery was installed and properly configured, everything returned to normal operation.

Thanks to everyone who replied. I took my A5 to a specialized workshop last week for the battery replacement. The diagnosis confirmed the auxiliary battery was indeed failing, causing all those electronic glitches. The total repair came to 320 Euro, which included the new battery, system resets, and a full diagnostic scan. The mechanic was thorough and explained everything clearly. The engine start is now perfect, and all those annoying warning lights have disappeared. The car electronics are working like new again. Really glad I didnt wait longer, as the tech mentioned it could have led to more expensive repairs if left unchecked. The whole service took about 3 hours, and they even did a post-repair test drive to ensure everything was working correctly. Much better experience than my previous mechanic, who missed the auxiliary battery issue completely. Sometimes paying a bit more for proper diagnosis saves money in the long run.