Pontiac Repair: 2001 pontiac grand am 6 cyl. gt, 6 cells, volt battery

Question
my car will only start 50% of the time. i have to get it jumped. auto zone said the battery is bad but it shows green. a friend hookd it up at the dealership an said something is still pulling 9 volts with the car OFF. WHAT DO YOU THINK. most of the time it starts fine but not always.

Answer
Hi
If the battery checks bad, and they said 9 volts, that REALLY sounds like a bad cell = bad battery.
If there was something "pulling" or drawing 9 (it would have to be AMPS), the battery would go dead in (about) between 1 to 1 and half hours (70-80 mins). That would be something REALLY big staying on, more likely multiple things.
The green eye or hydrometer is located in ONE cell. There are 6 cells in a 12 volt battery. So one cell MAY show good (green eye) and the cell next to it could be bad. That is the downside of the Green Eyed batteries, and as such GM no longer produces them. They are better at stating the whole battery state of charge, but not cell diagnosis.
I would replace the battery.
I hope this helps.
Good Luck
Pawl