V40 battery drain

I drive a V40 too, though a newer one, and had similar issues. Have you checked the battery terminals for corrosion or if they're loose? How old is your battery?

Thanks. The terminals are clean and connected properly. The battery is about three years old. Could a bad battery sensor be causing a parasitic drain?

A parasitic drain from a faulty battery sensor is possible. But without proper equipment, it's hard to say for sure. Given the symptoms, I'd suggest having the charging system checked by a technician at a good shop. The repair would be around 315€.

Thanks for the advice. I had it inspected, and it was a defective battery sensor. I replaced it, and the charging system is working now. Thanks again for the expert help.