Saturday I was out driving my car ('71 Dart GT 318) around town at speeds up to 50 mph. As the vehicle speed increased I noticed the voltage would also increase to just over 16V (which I do not recall seeing it ever go that high before). When I would come to a stop, with the transmission in Drive, the voltage would drop down to ~12V. During this trip I was not using anything electrical (wipers, headlamps, blower fan, etc...). Sunday, my wife and I took a drive to the cemetery (the 5th anniversary of her dad's passing), then to a local ice cream parlor. During this trip the voltage appeared to be normal (~12V at a stop and ~14V while at speed). This morning I drove it to work (as I had an appointment to drop it off at the body shop directly after work) with the headlamps on. Again, the voltage appeared to be functioning normally (~12V while stopped and ~14V at speed). After work, the volt gauge was reading just a hair under 10V no matter what speed I was traveling. Fortunately, I made it to the body shop without incident. Unfortunately, I cannot remember when I purchased the battery, but I'm sure it has to be at least 5 years old. The last time the battery died, it was a "sudden death" (as in, I shut the car off, and it would not re-start 5 minutes later). I've never experienced a "dying battery". Am I correct in assuming the battery is dying? Or?