Audi A8 Hybrid Battery Issues Impact Critical Systems

Had nearly identical issues with my 2017 Audi A7 Hybrid last winter and can share some relevant experience as a car owner with basic maintenance knowledge. The symptoms match what I encountered, weak starts, flickering lights, and error messages. Initially thought it was just a discharged vehicle battery, but the workshop diagnosed a faulty battery sensor, which was causing incorrect readings and affecting the electrical system management. The defective sensor meant the charging system wasnt properly regulating power distribution between the main and hybrid battery systems. After replacing the sensor for 315 Euro, all electrical issues cleared up and the battery charging returned to normal. To provide more specific guidance for your case, could you share: Are you noticing these issues mainly after the car sits unused? Have you checked the battery terminals for corrosion? What error codes is the system logging? How old is your current battery? These details would help determine if youre facing the same battery sensor issue or potentially something different in your electrical system setup.

Thanks for sharing your experience. My vehicle was last serviced at 165000 KM three months ago. After checking the battery terminals more closely, I noticed some white corrosion buildup around the positive terminal. Did a voltage test and found the car battery is only holding 11.8V when it should be around 12.6V. The system logs error code P0562 which indicates a system voltage problem. The issues do get worse after the car sits unused for a few days, suggesting a possible battery drain issue. Think I should start by cleaning the corroded terminals before exploring the sensor replacement you mentioned?

Based on the voltage reading and corrosion you found, cleaning the battery terminals should definitely be your first step. In my A7, similar corrosion buildup severely impacted the electrical system performance and contributed to the discharged battery issues. The P0562 code combined with 11.8V reading strongly suggests the vehicle battery isnt receiving proper charge. While my case ultimately required a sensor replacement, cleaning the corroded terminals resolved a significant portion of the electrical system issues initially. Here is what worked for me: 1. Clean terminals using a wire brush and baking soda solution 2. Check terminal clamps are tight after cleaning 3. Monitor voltage after cleaning, should rise closer to 12.6V 4. Test battery drain with a multimeter when car is off If cleaning doesnt improve the situation, then investigating the battery sensor would be the next logical step. My repair showed that sensor issues can mimic symptoms of a heavily discharged battery while actually being a separate electrical system problem. Would be helpful to know what voltage reading you get after a thorough terminal cleaning. This will indicate whether to pursue the sensor diagnosis route I ended up taking.

Thanks for the detailed suggestions. I cleaned the battery terminals thoroughly following your steps and retested the voltage, it improved to 12.2V but still not quite normal. The battery drain test showed a 75mA draw with everything off, which seems high. After a few test drives, the electrical system issues have improved somewhat but havent completely resolved. The lights flicker less, but cold starts are still weak. Given these results and the lingering P0562 code, I think youre right about checking the battery sensor next. Will schedule a diagnostic appointment to have them test the sensor specifically, since this matches so closely with what you experienced. The partial improvement from cleaning suggests multiple factors at play. Really appreciate you walking me through the troubleshooting process, it helped isolate the likely root cause without jumping straight to expensive repairs.