roadmaster4

Problem: battery light remains on with engine running, no load on the electrical system. Car is a 2008 Ford Edge, 46,000 miles, battery is only 1 and a half years old. Readings on the battery are 12.5 V at rest, all cells check out at 1.25~1.27 specific gravity on my hyrdrometer. Battery charges OK with a battery charger and rises to 13.8 V. Engine starts and runs fine, but there's only 11.83 V at the terminals with no load on the car. Connections are good. Is it the "buried" down deep alternator / regulator, or something else I'm missing. Thanks in advance for any advice.