Suzuki Kei Battery Drain Signals Major Electrical Issues

Had a similar situation with my 2004 Suzuki Swift. The symptoms match what I experienced, dim lights, starting problems, and dashboard warnings, which initially pointed to a dead battery. After inspection, the issue turned out to be more complex than a simple battery drain. The battery sensor was defective, causing inaccurate readings and preventing proper charging. The vehicle battery would appear discharged even when it was actually holding charge. The repair required: Testing the battery terminals and connections, Replacing the faulty battery sensor, Recalibrating the charging system, Running diagnostics to ensure proper communication between components This was a serious electrical issue that could have damaged other systems if left unaddressed. A defective battery sensor can cause the alternator to overwork and potentially fail. The battery itself tested fine, but the false readings from the sensor were causing the charging system to malfunction. Would strongly recommend getting the battery sensor tested specifically, not just the battery. These symptoms often get misdiagnosed as simple battery problems when the underlying issue is in the monitoring system.

Thanks for sharing that experience with the Swift. Really helpful since I just went through something similar with my Kei last month. The battery sensor ended up being fine in my case, but the alternator was failing to properly charge the car battery. The mechanic found heavy corrosion on the battery terminals which was causing serious battery drain issues. After a thorough cleaning and replacing the alternator, the low battery warnings disappeared and starting problems cleared up. Do you remember roughly how much you paid for your sensor repair? Also curious if youve had any recurring battery charging problems since getting it fixed?

Thanks for asking about the costs. After getting the faulty battery sensor replaced, my Swift has been running perfectly with no more battery charging problems. The heavily discharged battery issue completely resolved once the new sensor was installed and properly calibrated. The total repair came to 315€, which included diagnostic testing, parts, and labor. The car battery now maintains proper charge levels and the electrical system operates as it should. No more dim lights or starting troubles in the past months. The investment was worth it to prevent potential damage to other electrical components. Good to hear you got your alternator situation sorted out, corrosion can definitely cause serious battery failure if left unchecked.

Thanks for the input. Just wanted to wrap up my experience with the Kei. After the alternator and corrosion issues, I took it to a different mechanic who did a much better job explaining the problems. The repair bill came to 420€ total, bit steep but worth it to fix the constant battery drain issues. They cleaned all connections, replaced the alternator, and ran a full electrical system check to make sure there were no other problems lurking. Been about 3 weeks now and the car starts perfectly every time. No more dead battery scares or dashboard warning lights. Really glad I got a second opinion instead of just living with the dim lights and hard starts. The vehicle battery is holding charge like new again. For anyone dealing with similar symptoms, definitely get those terminals checked for corrosion first. Could save you from misdiagnosing a more serious electrical problem.