Please help as my girlfriend is giving me tons of crap for this.

I checked both the battery and the alternator with a voltmeter and the readings are good. I'm sort of confused at what the problem could be. I thought that maybe it was an ignition coil, but then the engine would run bad when on and that's not the case so i ruled that out too. the only thing i can think of is the remote car starter that's installed and i'm having best buy check that. any other ideas????

any help would be greatly appreciated.

p.s. a quick jump with cables will fire the engine up with no problems, but then why would the battery look good with the voltmeter????

 

How old is the car? Sounds like you need a new battery.
Voltmeter will only show 12 V., but it won't show Ampere (the # of units of 12 V. it can supply). You know 8 AA linked up to make 12 V (1.5 X 8 = 12) won't start you car. Have your battery tested at a shop.

 

I see that it's a 2003. I'll say your battery has served fairfully for the past 5 or more years. Time for a new one.