BMW 4-Series Battery Drain: Terminal 30 Warning Signs

Hey there! I had a similar issue with my 2017 BMW 3 Series (coming from a mechanic with moderate car experience). The symptoms were exactly like yours, battery warning, hard starts, and those annoying voltage alerts. My trusted mechanic diagnosed a heavily discharged battery that was on its last legs. They ran a full electrical test and confirmed the battery was the culprit, not the alternator or other electrical components. The fix was straightforward, battery replacement plus a system check, cost me about 290 Euro total. What's the mileage on your 4 Series? Also, any other electrical issues you've noticed, like flickering lights or weird behavior from your electronics? This info would help determine if you're facing the same problem I had. Take it to a shop ASAP though, driving with a failing battery can be risky and might damage other electrical components.

Thanks for sharing! My 4 Series has 122657 KM on it, and I just had a service done last month. The battery draining issue actually started pretty suddenly, no flickering lights or other electrical weirdness before this. The interesting part is that everything seems fine when the car is running, it's just the startup that's giving me trouble. I'm relieved to hear it might just be a battery issue like yours. Did you get an OEM battery or aftermarket? I'll definitely get it checked out this week, really hoping it's just the battery and not something more complex with the electrical system.

Hey again! Yeah, your situation sounds really similar to what I dealt with. I went with an OEM battery for my 3 Series because BMWs can be pretty finicky with aftermarket parts. The sudden onset of the problem is exactly what happened to me too, everything was fine one day, then boom, starting issues. When my battery was dying, I also noticed the car ran perfectly once it was started, just like yours. That's actually pretty typical for battery issues. The starter needs a lot of juice to get the engine going, but once it's running, the alternator takes over. Since you recently had service done, definitely mention that to your mechanic. Sometimes when they do diagnostic work, it can put extra strain on an already weak battery. My battery was about 4 years old when it failed, which is pretty normal for these cars. Just a heads up, make sure they register the new battery in the car's computer system when they replace it. I learned this the hard way, BMW batteries need to be coded to the car for optimal charging. The shop should know this, but it doesn't hurt to mention it. Let me know how it goes! Always happy to help out a fellow BMW owner.

Thanks so much for all the detailed info! That's super helpful about the OEM battery and especially about the registration in the computer system, I had no idea that was needed. I'll definitely make sure to bring that up when I take it in. I'm actually feeling pretty confident now that this is just a battery issue since our symptoms match up so closely. My battery's about 4 years old too, so the timing makes sense. I've already called the shop and booked it in for tomorrow morning. Will definitely mention the recent service and ask about the computer registration thing. Really appreciate you taking the time to share your experience, it's helped me feel a lot less worried about what could've been wrong. I'll update the thread once I get it sorted, in case anyone else runs into the same problem!