Lately I have a feeling my battery is on its way out. I drove the car today with the scanner hooked up and while cruising on the highway or running around city streets the battery voltage was 13.7V, at times it would go up to 13.8V.

I usually drive the car only like 2-3 times a week and is generally kept in the garage, sometimes I go over a week or so before taking it out for a spin.

Is 13.7V a bit low for battery voltage while running? I'm usually thinking it should be around 14.1V or so. Now after the sits for a few days and I start it it cranks a little bit longer than normal to start. Sometimes I have to start it twice for it to fire up, however once it starts and I do a few restarts after driving around it fires up no problem it's always that first start after the car's been sitting a while.

Am I looking at battery replacement #3 here?

 

looking at voltage isn;t gona tell you much. you need to head to a shop to get the charging system tested. a good load test will tell you if you have a problem

 

Yea, measuring charging voltage is testing the alternator. You would need to have the battery load tested. Your charging voltage looks normal BTW.

 

While not conclusive, your volage readings look good to me.

 

With my car running I hold 13.7-13.9 , so your charging voltage looks good.