My car has been sitting for like a month and a half.... battery is dead is it just from letting it sit?

 

Yeah i imagine. Stick it on a battery charger or jump it and let it run for a while, maybe take it for a drive (but don't go too far in case it craps out again) then let it sit over night and see what happens. I'd put my money on it just sitting too long.

GL!

 

^ Agreed. Jump it and let it run for like an hour. We used to do this all the time in my auto body class in high school.

 

Next time disconnect the negative terminal and it won't drain as fast while you're gone.

 

I'm gonna have to try this soon cuz I'm in the same predicament

 

Interesting. You'd think that in an auto shop, you'd know that an alternator could not recharge a battery from dead and that attempting to do so could actually shorten the life of the alternator...

Charge the battery and load test it. The alternator is designed to supplement power when running, maintain current state of the battery, and recharge what's been sucked out after starting the vehicle. If the battery is dead, the alternator wont bring it back, it needs to be charged properly to prevent it from happening again.