I experienced something very similar with my 2016 Porsche Panamera S E-Hybrid last month. Started with dim lights and sluggish starts, then got those annoying electrical warnings. Took it to my Porsche specialist, turned out it wasn't just the 12V battery, there was an issue with the voltage converter that manages power between the hybrid system and regular electrical components. They had to run a full diagnostic on both the conventional and hybrid electrical systems. The main fix involved replacing the DC-DC converter and recalibrating the battery management system. It wasn't just a simple battery swap like I initially thought. These hybrid Porsches have complex electrical systems that need proper diagnostic equipment to get to the root cause. Definitely recommend going to a certified Porsche technician who's familiar with hybrid systems. Terminal 30 issues aren't uncommon in these models, but you'll want someone who can properly diagnose whether it's that or something in the hybrid system. It was a serious repair job that took a couple of days, but it sorted out all the electrical gremlins.

Thanks a lot for sharing your experience! That's really helpful info. My issue sounds exactly like what you went through, same symptoms and everything. I'll definitely look into getting it checked by a Porsche specialist. By the way, do you remember roughly how much you ended up paying for the whole repair? Also, has everything been running smoothly since then, or have you noticed any other quirks?

Hey there! Thanks for asking about the follow-up. Happy to report that since getting my Panamera fixed, it's been running like a dream, no more electrical gremlins whatsoever! The total bill came to 290€ to sort out the battery issue and Terminal 30 interruption. Way less scary than I initially thought it might be, especially since I was worried it might be something more serious with the hybrid system. The Porsche specialist diagnosed it pretty quickly and, since the repair, I haven't had any dimming lights, startup issues, or those annoying warning messages on the dash. It's like having a new car again! The power delivery is smooth, and all the electrical systems are working perfectly. My advice would be to get it checked out sooner rather than later, these things can sometimes cascade into bigger problems if left unchecked. But sounds like you're catching it early, just like I did. Let me know how it goes with your Cayenne!

Here's how I would complete the conversation from's perspective: Thanks for the update! Just got back from the Porsche specialist you recommended, and I'm really glad I went. Turns out my situation was pretty similar to yours, but with a twist. They found that the DC-DC converter was going bad, plus some corrosion around the Terminal 30 connection. Total bill came to around 320€, a bit more than yours but still way better than I was expecting. The mechanic was super thorough, even showed me the old parts and explained everything. Took them about a day and a half to fix everything. Been driving it for a couple of days now, and what a difference! No more dimming lights, the start-up is strong, and those annoying warning lights are gone. The car feels way more responsive too, which I guess makes sense given all the electrical systems are working properly now. Really appreciate everyone's help here. Sometimes these car issues can be pretty stressful, but getting solid advice made the whole process much easier. Guess I've found my new go-to mechanic too!