BMW 5 Series Hybrid Battery Issues: Terminal 30 Problem?

Hey there! I have some experience working on hybrid vehicles and went through something very similar with my 2019 BMW 7 Series Hybrid last year. I faced the exact same symptoms, warning lights, starting issues, and those pesky undervoltage codes. Turned out my battery had degraded faster than expected and wasn't holding charge properly. Took it to my trusted workshop where they ran a comprehensive battery test that confirmed it needed replacement. The whole thing, including labor and diagnostics, set me back about 290 Euro, but it fixed the problem completely. Now it starts perfectly and no more warning lights. Before jumping to conclusions though, could you share how long you've had these symptoms and if you've noticed any pattern (like after short trips or when the car sits for several days)? Also, what's your typical driving pattern like? This info would help determine if you're dealing with the same issue I had.

Just had similar issues with my BMW 5 Series. Did my last service 2 months ago at 118388 KM and faced the same battery warning lights. The mechanics found that it was actually the voltage regulator acting up, not the battery itself. Surprisingly, the fix was quite straightforward and less expensive than a full battery replacement. They did a reset of the power management system first, which helped identify the actual problem. Have you checked if your car's battery charge is dropping more after short trips? That was a key indicator in my case. Might be worth getting the voltage regulator checked before replacing the whole battery. Just my two cents based on what I went through!

Hey again! Thanks for sharing your experience with the voltage regulator. Actually, you know what's interesting? After my battery replacement last year, I started having similar issues again about two months ago. Turns out I might've jumped the gun with the battery replacement. Did some more digging and yup, my voltage regulator was acting up too! Noticed the battery drain was especially bad after those quick grocery runs. The symptoms were pretty much identical to what you described. Wish I'd known about checking the voltage regulator first, could've saved myself some cash! Got it sorted at my regular workshop last week. They did that power management reset you mentioned and found the voltage regulator was the culprit. Much cheaper fix than the battery replacement I went through earlier. My 7 Series is running like a dream now. Just goes to show there's usually more than one possible cause for these electrical gremlins. Thanks for bringing this up, might help other BMW hybrid owners save some money and headaches. Have you had any issues since your repair?

Thanks everyone for the detailed responses! After taking your advice, I had my car thoroughly checked. It's such a relief to know I'm not the only one who's dealt with these issues. You were right about checking the voltage regulator, that turned out to be my problem too. The mechanic did the power management reset and replaced the faulty regulator. The whole repair came to about 200 Euro, which was way better than what I was expecting to pay for a new battery. The car's been running perfectly for the past week, no more warning lights, starts up right away, and the battery charge is staying stable even after those short trips that used to cause problems. Really glad I asked here before rushing into a battery replacement! Just wanted to update everyone and say thanks for steering me in the right direction. It's great to have such helpful community feedback. Will definitely keep an eye on the charging system from now on and watch out for any similar symptoms.