Q7's Multiple Electrical Issues Point to Failing Battery

Had similar electrical problems with my Q8 2018. The symptoms matched exactly, dim lights, sluggish start, and fluctuating dash display. Initial checks revealed a voltage drop when starting. The root cause turned out to be more than just a weak battery. The voltage regulator in the alternator was failing, causing inconsistent power supply to the electrical system. This created a chain reaction where the battery was not getting properly charged during drives. The repair required: Full diagnostic of electrical system, Replacement of alternator assembly, New battery installation, Testing of all major electrical components It was a serious issue that needed immediate attention as it could have left me stranded. The failing alternator was steadily degrading the battery health. The repair prevented potential damage to other electrical components in the vehicle. These symptoms almost always indicate more than just a battery problem. The inconsistent voltage output affects multiple vehicle systems. Getting it diagnosed properly is crucial, as replacing just the battery would have been a temporary fix. Would recommend having both the charging system and battery load tested to identify the full scope of the electrical problem.

Thanks for sharing your experience. My Q7 had nearly identical charging system issues a few months back. Definitely sounds like the same alternator issue you described with that unstable power supply. The battery terminal connections were actually corroded too, making the voltage problems even worse. Did you have any similar corrosion when they checked yours? Would be really helpful to know the total repair cost from your fix, might give me a ballpark for what to expect. Has everything been running smoothly since the repairs, or have you noticed any other electrical quirks?

Glad I could help with the alternator issue insight. My final repair actually turned out simpler than expected, the main problem was a heavily discharged battery that needed replacement. After the charging system diagnostic check, they found the battery was the core issue, not the alternator. The total cost came to 290 Euro for the replacement and testing. Much better than what I initially feared with potential alternator problems. Since the fix, the electrical system has been running perfectly, no more voltage drop issues or starting problems. The battery terminals on mine were clean, so no corrosion problems in my case. That could definitely explain the extra charging system complications you experienced. Low voltage symptoms can get worse when corrosion interferes with proper battery connections. The undervoltage warning is completely gone now, and all electrical components are working as they should. Worth every cent for the peace of mind knowing the charging system is back to normal.

Thanks for the advice. Finally got my Q7 sorted last week. Turned out the voltage regulator was shot, causing all those charging system problems. The mechanic found heavy corrosion on the battery terminals too, which made the electrical issues even worse. The repair included: New voltage regulator, Battery terminal cleaning and replacement, Full system diagnostic, Battery load test Total cost was 430 Euro, which included parts and labor. Not cheap, but worth it since the car starts perfectly now. No more flickering lights or voltage drop when starting. The charging system is working like new. Much better experience with this mechanic, they actually showed me the failed parts and explained everything. Definitely feel better about the whole repair process this time around.