Prius Weak Battery Sensor

Greetings. While I haven't worked on a Prius specifically, your symptoms sound remarkably similar to an issue I encountered with my 2016 BMW 330e. Weak starting and flickering lights are often indicative of voltage irregularities. Have you performed any preliminary battery testing, specifically monitoring the battery voltage under load and at rest? A defective battery sensor can certainly cause these problems by providing incorrect data to the car's computer, leading to improper charging cycles and ultimately premature battery degradation.

Thanks for the info! I haven't done any voltage testing myself. Where exactly is the battery sensor located, and is it something I could test with a multimeter, or should I just take it to a professional?

While the exact location of the battery sensor can vary, it's typically integrated into the battery management system, often residing directly on or near the battery pack itself. Yes, a multimeter can be used to assess the sensor's output, but interpreting those readings accurately requires a solid understanding of the system's expected parameters. Given the complexity of hybrid systems and the potential safety concerns associated with high-voltage batteries, I would strongly recommend entrusting this diagnostic procedure to a qualified technician. Incorrectly probing or disconnecting components could lead to further damage or even personal injury. Best to let a professional assess the battery health and sensor functionality.

Okay, I appreciate the advice. I took it to a workshop, and you were right – it was a defective battery sensor. The total repair cost was 315€. Thanks again for the help!