Sunny battery issues

Hey there! I had a similar problem with my Nissan Sunny (don't remember the year exactly). Weak starts and flickering lights sound familiar. Have you had the battery health checked? It could be a faulty battery sensor messing with the voltage regulation. Much like a faulty thermostat can give wrong temp readings, a bad sensor gives bad battery health readings.

Thanks for the quick reply! I haven't specifically checked the battery sensor. How would I go about testing that? Is it something I can do myself with a multimeter, or is it better left to a professional?

While you could try testing the sensor with a multimeter, it can be tricky to interpret the readings without the proper equipment and experience. Think of it like trying to diagnose a heart problem with just a stethoscope. You might hear something, but you won't know the full picture. I'd recommend taking it to a workshop to get a proper battery test. My issue turned out to be a defective battery sensor and replacing it solved the problem.

Thanks so much for the advice! I suspected it might be something like that. I'll take it to a workshop and have them check the battery sensor specifically. Your experience is really helpful. I saw a similar case and the repair cost was around 315€. Hopefully, that's all it is!