I had my first flight of my plane today. The only issue I had was an intermittent high voltage warning 15.0 volts. Amps were always in the green at +2-3 amps. I landing the plane and checked the grounding between the voltage regulator and the battery. It was OK, but I went ahead and removed the VR and made sure the ground to the airframe was good. I also added a ground strap from the VR to the engine. Second flight, same thing, intermittent High Voltage. Could I have a bad battery?? Help