Ford: charging system, 2007 ford taurus, ford taurus

Question
My 2007 Ford Taurus keeps saying to check the charging system, what does this mean? Check the battery or alternator?

Answer
It means to check your alternator.  You should be getting a charge of atleast 13 volts or higher.  Take a multimeter and with the car off, put it on the battery and record your reading.  Then start the car up.  The amount of voltage should increase.  If it does make sure like i said its atleast 13 volts or higher.  Now this does not mean that the battery is good.  The alternator may be putting out a charge but the battery may not be taking it and holding.  If you suspect bad battery you can take it a local auto parts store and they can load test it for you.