Peugeot 107 Battery Drain

I understand you're experiencing a heavily discharged battery in your Peugeot 107. These symptoms: error messages, flickering lights, recorded errors, and weak starting performance indeed point to a battery or charging system issue. Have you checked the battery's voltage when the engine is off and while it's running? Also, were all electrical consumers switched off during testing?

Nah, I haven't checked the voltages myself. Don't have the gear, to be honest. But could it be something besides the battery itself that's draining it?

Indeed, there are various possibilities. A defective battery sensor is potentially at fault, causing excessive drainage. Given the complexity and potential for misdiagnosis, and as you lack testing equipment, I suggest consulting a qualified workshop to inspect the electrical system comprehensively. The repair cost will probably be around 315€.

You were spot on! Took it to a garage, and it was the battery sensor causing all the trouble. Cost me 315€ as you predicted to get it sorted, but at least it's running smoothly now. Thanks for your help!