I noticed my voltage varies while driving the car from a steady 14.1 volts down to 13.1 or around there. The car really feels like it runs better at the 14 volts. smoother and with quicker throttle response. Is there an external voltage regulator or is it built into the alternator? Is this actually a problem or am I imagining things? Is .5 or 1 volt enough to even be noticeable? Maybe I am going crazy and this is a sign I need more sleep?

 

Its fine, the battery can sometimes drop down to 11.1~14.8V in some cases. It all depends on the required loads. When you start you will find that its charged up to its maximum potential stating the obvious but as the demand on startup for current is a lot higher then any other load.

 

so the voltage should have no effect on the performance of the car is what you are saying. that is what I thought, I just wanted to double check. Cheers

 

Unless you drop beyond a certain point, but you will notice a lot of other things happening, one is mainly not starting your car.

 

How can you check how much battery life is left??

 

Take your battery to any local Canadian Tire or parts store and they should test it for you for free. You will have to take the battery out of the car and bring it into the store.

 

You need to sand the battery terminals and put some grease on it. It should stop the problem. It looks like your battery is 3 to 4 years old and you will need a new one next year.
If your battery goes bad you will be changing lightbulbs more often and they will burn out 3 or 4 at once as the alternator tries to charge bad battery with 14.5 or 15 V.
At such time you need new battery yesterday.

 

To tell how much life is left you could open the caps and look inside. If you see white powder like inside residue the battery will need replacement. This residue is Sulphite that will not dissolve back.This is what kills our batteries in 6 year time.

 

The battery is less than 2 years old. I doubt any issues are from the battery. I would assume there is a built in voltage regulator on the alternator and it is slowly failing?

 

Did you clean or sand the positive terminal?
Did you check acid level?