Hyundai Repair: My hyundai Sonata is having difficulty starting., 2002 hyundai sonata, hyundai sonata

Question
I have a 2002 Hyundai Sonata. Used.  I recently purchased a NEW battery in april. I bought it because the shop told me that my old battery had no juice in it left.  I did have lil issues here and there with it not starting, but I thought it was my fault.  Leaving a light on or what not.  However, I am having the same issues again. These past two days.  I do not understand it? what am I supposed to do.  I have needed a jump twice in the past few days where the car is completely dead.  Do you think there is something that is running my battery down? what could it be?

Answer
There are three types of problems that could cause your symptoms:

1.  The battery could be defective.  Even though you purchased it in April, the potential is still there (although the probability isn't as high) that the battery is the problem.

2.  The alternator may not be charging the battery.  In this case, you may notice dim lights when driving at night, the air bag lamp is likely come on, and the problem with the vehicle not starting is most likely to occur when the vehicle has been sitting for only a short period of time.  A quick (although not thorough) way to check the alternator is to place a voltmeter on the battery terminals when the engine is running.  The voltage should typically be between 13.5 and 14.5 Volts.

3.  There may be something in your car staying on and draining your battery.  The name for this drain is parasitic draw.  In this case, the symptoms will most likely occur after the vehicle has been sitting overnight or longer.  To test, you'll need to install an ammeter in-line between the negative battery terminal and the battery post.  If the draw exceeds 50mA, it's too much.  If it exceeds 100mA, it's likely to cause your symptoms.