I'm on the second alternator for my car. This one prolly has 65K miles plus on it and is about 10 years old. Just cranked it up and after 5 minutes or so the RPMs flutter and the lights flicker and the battery gauge is all over the place. Is this a sign of a dying alternator and is this why my car eats up red top batteries?

 

Check the voltage at the battery with engine at idle, should read around 13.8~14.2 volts... How old is the red top??? I believe there was a problem with Optima batteries a few years ago, not holding charges...

 

Ya. This is my 3rd red top, it's brand new.

 

Take it to an auto parts store to have it load tested..Might have a bad cell....

 

A failing battery can cause RPM drop and flickering lights? I always thought that would be an alternator going bad??

The symptoms do get worse when the car is in gear though.