Rep Power: 252

had my car sit in the airport parking lot for 3 weeks and of course i knew the battery would be dead when i got bak. when i did get bak my car was just covered in snow and was freezing out, considering its IL its expected. so i had it jumped and started right up but when i turned on my headlights the car wanted to die. i did leave the vehicle running for several minutes while i was gettin the snow off the car and around it. got home just fine but today the car was dead again.

now im wondering if its a bad battery, just too cold and not holding its charge, or could it even b a bad alternator? wouldnt b even worth trying to get it tested at the auto store since its pretty much needs a jump and wouldnt b at its testings spec. so wat do u guys think i should do? new battery? battery is about 3-4 years old.

 
Rep Power: 794

possibly new battery. usually after 2 weeks its drained enough that you cant start the car. do you have a trickle charger you can hook up? the alternator cannot charge the battery much, unless you drive on the freeway for an hour at least. and being cold, battery will have even more problems. try to charge the old one, then get a new battery if the old one isnt holding charge. i doubt its anything more serious. if alternator was bad, the battery light would come on.

 
Rep Power: 212

yeah definitely the battery. your car was dead and in freezing weather that whole time, so you probably need a new one. when its completely dead like that you need to leave it on or drive for a long time before it has enough juice to start up again the next time. it wont have anything to do with the alternator, because it started up and ran fine once you got the boost.

 
Rep Power: 238

ya get a decent trickle charger and keep it on low i personally would use this as an excuse to get a bigger and better battery something with higer cold crank amps like a duralast gold top. next time definitely get a ride or take a cab or a bus or something i would be to worried to leave my car in a parking lot for 3 weeks.

 
Rep Power: 273

i left my car sitting for 5 weeks when i was at military training and it started right up. battery was about a year old.

 
Rep Power: 238

was it freezing when you left it because cold drains batteries they dont even recommend storing them on concrete floors.

 
Rep Power: 273

no, it was in May/June.

 
Rep Power: 0

I have the Optima red top: 980CA / 800CCA. I haven't had any problems starting in cold weather. As this battery is bigger than stock, you must remove the battery tray and just set the battery on the little shelf that sticks out. The only down side is that the battery did cost $180, but, it's well worth the investment.

 
Rep Power: 252

sorry for late response. just went ahead and got a new battery that night since i had school the next day. pretty sure the battery was on its way out and was prob good that i had it replaced.

 
Rep Power: 0

Ahhhh, Okay first of all, when you tried starting the car, did it crank at all? If it Cranked it isn't your battery, knowing that it cranks shows there is still voltage going to the starter and alternator. Don't always assume it is your battery, because it isn't. If you live in cold weather areas the Alcohol content in your fuel could have evaporated and it was a poor start up and that could show when your car was weak like you stated. You could have an injector leak, Spark plugs were bad, or poor spark plug wires. Knowing that it cranks means IT IS NOT Your battery!

 
Rep Power: 794

good point. since gas companies factor in added ethanol to determine final octane, gas with the ethanol removed would be lower than 87 octane.

 
Rep Power: 252

doubt its any of those considering my car starts fine now with a new battery. and no it never cranked. even with the car running for several minutes and after driving it would never start bak up. no crank just lights would be on but dim. thanks for the input tho.

 
Rep Power: 191

I would disagree, just because the engine cranks does not mean it is not your battery. Most electronic ignitions have a threshold voltage for them to work. If the module must see at least 10.7 volts and you are only supplying 10.6 volts the engine will crank but there will be no spark. A battery needs to be tested under load to verify that it can put out the required amps at sufficient voltage. You can have a battery with a bad or weak cell that puts out enough power to crank but not start an engine.
You can also see a similar effect trying to jump a car. Cheap jumper cables can do the same thing, supply enough power to crank the engine but not enough voltage to enable the electronic ignition to work.