2013 Mitsubishi Outlander. Newer battery, but car sometimes won’t crank over. Then battery dies. When it gets jumped it usually starts and will start for a week or two then same problem.
Start the car and then while it is started take off the positive cable if it dies it's the alternator it kind of sounds like that could be it but I might be wrong if anything take the starter off and get it tested at a parts store you can also try when you're trying to start it and it wont crank hit the starter with a hammer not too hard tapping a bunch of times and if it starts then you know it's the starter