ok, so i i go to my car and try to start it. when i turn the key to try and start it, it cranks, but very slowly gets slower and slower and stops cranking. the car stil gets electricity but not enough to start the car. i jumpstart it, starts up perfectly, drove it on the freeway for an hour, ran fine. turn it off for 4 hours, tryed to start it, cranked slowly but managed to start, drove it around again for about 30 min then took it home and shut it off. tryed to start it again after 6 hours, cranked really slowly and failed to start. im guessing its my altenater since i drove it everytime i jumpstarted it, but wont have enough energy to start again. checked the grounds, cleaned them, but no luck. im going to see if the battery has sufficient energy and if it does, its prob my alternater. can anyone confirm this or is it something else?

 

It sounds like it is a failing battery. You need to take a voltmeter and test the volts at the battery with the car running. It should be in the upper 13's or low 14's if it is much under that then the alternator is going out. If not then I would think it is the battery.

 

hmm, could be cause i left my radar dectector plugged in the cigarette lighter overnight a few days ago. but when i jumpstarted it, it ran fine and would always crank perfectly till now. i thought the detector being off wouldnt drain my battery but i guess it did?

 

test it, if your still not sure Autozone tests it for free, if the battery just needs a recharge then take your alternator to them and have that tested. Like 1sweet7 said it could be either one depending on the voltage.