CT4 BW Red battery light/voltage drop?

[LastGas]

Anyone experienced the red battery light and seen the voltage drop back down to 12 volts? Happened to me yesterday. Parked the car and had it towed to the dealer. Usual guess would be a failed alternator, although I don't hear about that as a failure point on the lf4. Car has 3 years and 20,000 mi, about 15 track days.

Light was off when I restarted the car to move it off the flatbed and park it at the dealer. Dealer here has a history of incompetence so wish me luck!

 

[rdollie]

Occam's razor - start simple meaning battery failure (due to age) before alternator. My 5BW is throwing codes now 100% consistent with needing a battery after 4 years.

 

[ngoni]

You can go to any auto parts store and they'll test your battery for you. Or if you have a multimeter, you can DIY:

How To Test a Car Battery With a Multimeter - Haynes Manuals

Keep your vehicle in top shape with tips and tutorials on the Haynes blog. Read our post 'How To Test a Car Battery With a Multimeter' today and see if it's time to buy a new one or if the battery just needs a top-up

us.haynes.com

 

[LastGas]

Conclusion, it appears it was a battery problem. Symptoms were surprising because it was a voltage issue when running. Not a starting issue.