Altima Won't Start
I have a 2001 Nissan Altima that won't start. I checked the battery and it was about 7.5v. I jumped it; started and ran fine. I let it run a while, shut it off, waited a bit again and tried to start. Nothing. Battery was around 10-11v. I disconnected the battery, replaced the neg terminal (was loose), and cleaned the posts/terminals. Reconnect battery and checked the voltage: was about 4.5v now.
The alternator is only a few months old, and the battery is maybe 1-2 years old (it's a factory 2nd). Does it seem like a bad battery is the culprit? Or is there something draining it? Any way to further test/troubleshoot? The issue started after we came back from a vacation and the car had sat for a few days. Any help or suggestions greatly appreciated!