Ccrosser weak battery flickering lights

I had similar issues with my Ccrosser. The weak battery and flickering lights point to a possible charging problem. Have you checked the battery voltage when the engine is running? Should be around 14V. If it's lower, the battery isn't getting enough charge. It could indeed be the battery sensor, or the alternator itself.

Thanks for the quick reply! How would I test the voltage on my battery?

You'll need a multimeter. Set it to DC voltage, something like 20V range should do. Connect the red lead to the positive terminal of the battery, and the black lead to the negative. Check the voltage with the engine off (should be around 12.6V if the battery is healthy). Then start the engine and check again. If it's not going up to around 14V, your battery isn't charging properly. Best to get it checked by a workshop, as a defective battery sensor can cause all sorts of electrical issues. It could also be an indication of a bad alternator.

Thanks, I'll get the voltage tested. I took it to the workshop and it turned out to be the battery sensor. Repair cost 315€, but the car is now working perfectly again!