Dying Audi A2 Battery Points to Alternator Crisis

My Audi A4 2005 1.8T had nearly identical symptoms last season. The initial low voltage signs were dim headlights and inconsistent power windows operation. The charging system test revealed both a failing voltage regulator and a heavily discharged battery that wouldn't hold proper charge anymore. The root cause was actually a chain reaction, the voltage regulator in the alternator started failing first, leading to improper battery charging over several months. This continuous undercharging damaged the battery cells permanently. The voltage drop became severe enough to affect multiple electrical systems. The repair required: Complete alternator replacement (voltage regulator is integrated), New battery installation, Testing of the entire charging system, Cleaning and securing all battery terminals This was a serious issue that needed immediate attention since it could have left me stranded anywhere. The battery voltage reading was down to 10.8V when it should maintain around 12.6V when fully charged. The symptoms matched the classic signs of charging system failure: Weak starting power, Flickering lights, Unusual electrical system failures, Battery warning light appearing intermittently Testing the charging system output is crucial before just replacing the battery, as a new battery would likely fail again if the underlying charging issue isn't fixed first.

Thanks for sharing that detailed experience with your A4. The same alternator issue happened with my A2 last month, weak starts and electrical problems all around. The charging system was totally shot and needed replacing. Since you mentioned having both the alternator and battery replaced, would you mind sharing how much that repair ended up costing you? Also, has everything been working properly since the fix, or have you noticed any other electrical problems popping up?

The alternator and battery replacement on my A4 fixed all electrical problems completely. The voltage drop issues never returned after getting it properly diagnosed and repaired. The undervoltage detected by the system was resolved once the new parts were installed. The total repair came to 290 Euro for resolving the heavily discharged battery condition. This included a complete power supply system check to ensure the charging system was functioning correctly. The battery voltage now stays steady at normal levels, and all electrical components work perfectly. No more flickering lights or system failures since the repair. Was definitely worth addressing the root cause rather than just trying quick fixes. A proper diagnosis of the charging system prevented any future electrical problems from developing. Good to know your A2 is getting similar repairs done. These symptoms really point to classic charging system failure patterns, and fixing both components together is usually the right approach.

Had my A2 fixed last week after getting your advice. The mechanic confirmed the charging system diagnosis, exactly what you described with the alternator and battery both needing replacement. Total bill came to 320 Euro, bit more than yours but included a full electrical system check. The battery terminal connections were also pretty corroded, so they cleaned those up while doing the work. Really glad I got it all done properly instead of just trying to replace the battery alone. The charging system is working perfectly now, no more flickering lights or weak starts. Battery voltage stays steady at normal levels. What a relief to have reliable power again. Thanks for helping me avoid a partial fix that would have likely failed again. This kind of repair definitely needs proper diagnosis and complete solution.