I have a Kohler style 20amp alternator with an external rectifier/regulator in the Sonerai. I installed an alt. warning light/circuit and removed the analog volt meter to make room for a G-meter. The old analog volt meter showed about 14.5vdc inflight. But, the alt. warning light indicates an occasional over voltage condition. I put a digital volt meter across the battery terminals and went flying. It shows 15.3 - 15.4vdc when the over volts condition is indicated. Apparently, the alt warning circuit's over-volt threshold is set to 15.2 volts. My question: How high is too high? I've heard that automotive type charging circuits can see as high as 16vdc.