Battery loses power after a few days outside. Not alternator, battery, starter..

Hello, have you checked the battery directly to ensure it is fully charged and able to sustain a load? Most times you'll find the battery is the culprit and area of concern. Beyond that, a parasitic draw test should be performed. https://repairpal.com/parasitic-drain-diagnosis Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops