Yaris weak battery and flickering lights

Hey, I had a similar issue with my Yaris a while back. I'd check the battery sensor. What's the battery voltage like when the engine is running?

Where do I check the battery sensor and how do I measure voltage? I'm not super tech-savvy, but I'm willing to give it a shot if it's easy enough.

Yeah, it's probably easier to just take it to a workshop. My battery sensor was defective and causing similar symptoms. They can test the battery and charging system to confirm. I bet that's your problem too. Saves time and maybe frustration.

Thanks for the advice! Turns out it was the battery sensor. Cost me 315€ to get it replaced, but the car's starting perfectly now.