Peugeot 307 Undervoltage Error

Hey! Similar thing happened with my 307. By undervoltage, do you mean everything's kinda dim and struggling, especially in the mornings? It was driving me nuts. Did you check for any voltage drop across the battery terminals?

Yes, that's a good description, more noticeable in the mornings. Where exactly should I measure voltage drop and what values indicate a problem?

Right, that sounds super familiar. I'm no expert, but after chasing my tail, a workshop sorted it. They ran a full battery health check and power supply diagnostic. Honestly, save yourself the hassle and just get it checked out by a pro.

Thanks for the advice. A workshop visit was best. Mechanic confirmed the battery was heavily discharged. Replaced it and the issue is resolved. Repair cost 290€.