67 Barracuda Heavy Electric Load
Okay, I finally seem to have a workable solution. First off I picked up my alternator and had it tested (for free) at two other shops. Bottom line is that all three places said the alternator was okay. My conclusion on the alternator is that the car was not being driven at enough high speeds because I often drove around the neighborhood at 35 MPH speeds and idling at local events/friends. So the alternator is back on the car.
Here are some changes I made:
1. Bought and installed a new Optima yellow top battery. The yellow top is marketed as being a dual purpose battery that can handle both starting and extra electrical accessories - such as my electric cooling fan.
2. I called and spoke with a tech at Battery Tender about my Battery Tender Jr charger. My purpose in calling him was to find out if I needed the new Battery Tender Plus charger because of the 72 amp hours rated on the yellow top Optima. He explained that the charging program was the same on all the Battery Tender products except for the rate of charge, and the hours until timeout. I got my volt meter and he stepped me through the charger light color changing/flashing and their meaning on the charger output. The Battery Tender Jr charger output up to 14.6 volts on red then gradually came down to 13.2 volts when flashing green and stayed there on solid green. So our conclusion was that the yellow top Optima was being charged properly. The potential problem with the Batter Tender Jr charger is that the 80 hour safety cutoff may be reached before fully charging an excessively discharged yellow top Optima. So after 80 hours, the charger stays solid red and is no longer charging unless you unplug/replug to reset the timer. A Battery Tender Plus puts out more amps and stays on longer to successfully charge a yellow top Optima battery without having to be reset.
I had noticed when using the red top Optima that the Battery Tender Jr sometimes stayed solid red and I did not understand that the charger was in safety shutoff mode. So the final piece of the puzzle was to hook-up the Battery Tender Jr when finished driving and make sure it is solid green before taking the car out for a spin. My driving of the car once a week and low speeds was the culprit along with poor battery charging habits. I have not timed out the Battery Tender Jr charger so far with the yellow top Optima when making sure to hook it up immediately after driving.
Another easy test I tried was disconnecting the battery when idling under full electrical load. The car shuts off unless I rev up the motor. So I will be sure to get the car up to highway speed for a while when driving.
So my only additional cost was a new battery. The red top Optima was dated 12/16 anyway so it was time even though it tested okay. Sorry for the long post and hope this helps others.