Subaru Legacy battery keeps dying despite multiple replacements, possible drain issue on Subaru Legacy

Some Subaru Legacy owners report experiencing persistent battery drain issues despite multiple replacements, often linked to a parasitic battery drain problem. Common causes include loose electrical connections, damaged wires, or corrosion on battery terminals that can disrupt current flow and create bad connections. Additionally, certain devices or components, such as interior lights, aftermarket installations, or faulty alarm systems, may continue to consume power when the vehicle is off. Some models, particularly the Legacy and Outback with 2.5-liter engines, are known to suffer from premature dead batteries due to parasitic draw from electronic components. Furthermore, a malfunctioning alternator may also contribute to the battery drain over time. To mitigate these issues, owners are advised to regularly check and clean battery terminals, drive longer distances for proper recharging, and consider removing the DCM fuse if parasitic drain is suspected. If problems persist, consulting a professional mechanic or Subaru dealership for diagnosis and resolution is recommended.