I have a 2008 Avenger R/T. I've been having some trouble with spontaneous no-starts, and Check Engine light on intermittently. I retrieved the codes and got P0562 (Low Voltage). I work in a Ford dealership (I know!) and got one of my techs to take a look. He told me my battery was not holding a charge whatsoever, and I probably needed an alternator. He said I shouldn't even try to drive it because it might die on me. Well, later in the day he had some more time and decided to try to run a pinpoint diag because he said he wanted to be really 100% sure it was the alternator. When he tried to do more tests, the charging system all seemed suddenly fine. We held off on the alternator. Now the Check Engine Light is back and so is the P0562 code, and no one really knows for sure what the problem is. Battery is testing fine. Sorry, I'm not as knowledgeable as most here about this, but I'm concerned even my techs can't figure it out. Although, they are Ford mechanics
Does anyone have any idea about this?

 

How old is the battery in your car. If it is the original, it is due for a change. Next is all the battery connection points. These all need to be cleaned and coated with dielectric grease and retightened.

1 battery clamps - and +
2 cable to clamp at the battery side
3 both the positive and negative jumper points

all these connection points need to be wire brushed to bare metal and coated with dielectric grease before reassembly.

Also look at any body grounds in the engine compartment and clean dielectric grease and retighten.

This should give you a good starting point.
I had a 1 year old battery that the voltage was fine but the cold crank amps were way down and caused some problems on my 08.