minus 19…and doesn’t concern…

Hello, I was expecting… 2.0 petrol I start, starter also goes crazy, motor runs about 2-3sec. and boom isser out again. no chance to start the part. I then gave up to not empty the battery. at minus 10 it was still quite cumbersome and tired. (Has always left out all the consumers when driving to give the battery a chance to charge) …hasn’t helped anything… could that be the battery? although it’s not quite dead yet?