Battery Woes: Mitsubishi 380 Electrical Mystery

Hey there! I have some experience with car repairs and I ran into a really similar issue with my 2009 Mitsubishi Lancer (pretty close to your 380!). I also own a Mitsubishi Eclipse. The symptoms were exactly like yours, sluggish starts, dim lights, weak battery. Took it to my regular workshop and turned out the battery sensor was faulty, which was draining the battery even when the car was off. The fix cost me around 315 Euro but solved the problem completely. Quick question, have you noticed if the battery drains even after short periods of not using the car? And what's your battery's age? This info would help me give you more specific advice based on my experience. BTW, if you're seeing other electrical issues besides these symptoms, let me know. Sometimes these things can be connected to other problems.

Thanks for the detailed reply! Yeah, the battery seems to drain even if I leave it parked overnight. The battery's about 2 years old, and my last service was just 3 months ago at 81452 KM. I'll definitely check out the battery sensor, didn't think of that! Good to know it might not be too expensive to fix. Anyone else had similar experiences with the 380?

Hey again! Fellow Mitsubishi owner here. After seeing your update about the overnight drain and battery age, I'm even more convinced it's similar to what I dealt with on my Lancer. You know what's interesting? When my battery sensor issue started, I also noticed the drain was happening really fast, like overnight, just like yours. And my battery was actually newer than yours (only about a year old) when the problems began. Since your battery's two years old and you're getting these symptoms, I'd definitely push to get that sensor checked first. Quick tip from my experience, before you head to the workshop, you might want to do a quick check: next time you park at night, try disconnecting the negative terminal (safely, of course) and see if the battery holds charge better. That's what I did, and it helped confirm it was an electrical drain rather than just a dying battery. By the way, after fixing the sensor on my Lancer, I haven't had a single issue in the past 8 months. And since our cars are pretty similar (Mitsubishi's electrical systems don't vary too much between models), I think you might be looking at a similar fix. Let me know how it goes, I'm curious if it turns out to be the same issue!

Thanks so much for all this helpful info! I'll definitely try that negative terminal test tonight, that's such a smart way to check if it's an electrical drain. It's really reassuring to hear you haven't had any issues since fixing the sensor. I've actually just booked my car in at the workshop for tomorrow morning, and I'll specifically ask them to check the battery sensor. Really appreciate you sharing your experience, makes me feel a lot better knowing it's probably not something super major or expensive. I'll update this thread once I get it sorted, in case anyone else runs into the same problem with their 380!