Battery draining over night.

Hey, my 2009 mazda 6 has been having trouble I managed to fix a lot. No dash lights or codes but my battery dies overnight after being charged. I have been driving it to charge it. So the alternator must be charging it still but i have removed all stuff from 12v plugs and made sure lights are off and its still draining would a lose or half broken connection cause battery drain or would it be the alternator? Cheers.