subaru has is a long…
Subaru has is a long standing "feature" related to its "Starlink" (think OnSat) system. Starting in about 2017, in it's Outback and related models, it's DCM (communication unit for Starlink) is wired to be on continuously whether the ignition is on. About the late 2020, the national cellular 2G and 3G networks were shutdown which the DSM uses.. The DSM was programmed to constantly connect and at that point it panics to have lost communication causes it essentially try to "Phone Home!" continually while the car was turned off. In my case (and many others) the battery would last about 5 days before it was dead and damage itself. Subaru blamed me and other owners because we didn't drive the car enough on long trips. Subaru was sued in a class action suit, and replaced my battery 4 times when my battery died, but didn't acknowledge the actual problem just the symptoms. A shade tree mechanic found the problem and came up with a simple solution for under $10 in parts.
. . . We went back to Toyota and a new RAV4 Prime, since Toyota takes responsibility for their vehicles and values their customers.
Google "Outback Battery Drain Problem " for more info