Get a voltmeter and check the voltage while the engine is running. If the alternator is charging correctly, you should see a reading of somewhere between 13.5 and 14.5 volts at the battery. If it is below 13.5, the alternator is shot.
If the battery is older, one or more of the cells may have deteriorated to the point where the battery will not hold a charge. A healthy battery should be somewhere between 12.4 and 12.8 volts when it is fully charged. Some drainage overnight is expected for modern vehicles due to the constant drain the various electronic components place on the battery while the vehicle sits but this is not an issue as long as the battery is healthy.
You need to look at the alternator and it's charging abilities. You are charging the battery so it is holding a charge and recharging off the car. Also When the car is off it may not be all the way off as in something is still drawing power erroneously. A bad alternator can do this but other things can too. Your battery is taking a beating here but I don't agree that it is the problem today. Knowledge of a voltmeter would help here.
How old is the battery? If it's 5 yrs old, then it's about time.
battery!!
My car dies after being charged. A day later, it's completely dead--- No lights, no engine, no start, no nothing. When I recharge the battery, it starts up and drives fine, but then after sitting for a while it dies. I just want to know if this is the battery or alternator??? I don't want to have to pay to get it taken to shop just for them to tell me what's wrong, I want to just get this out of the way so I can have my baby back. :(
What do you think is wrong with my car?
