Voltage Regulator??

Battery technology has changed a lot over the years too. Put a OEM type battery in there and throw a continuous 14+ volts at it. The top of it would stay damp as it boiled water from the multiple caps, rotted away battery tray and underside of the hood.
Todays batteries that stand at nearly 13 volts and store 6 to 900 cold cranking amps have no problem with 13.8 to 14.2 charging systems. Look at it periodically though. If it gets damp on top or a sidewall swells, something is wrong, most likely the battery itself. A bad battery can cause constant overcharging. In that case the alternator and regulator are doing what they should with the signal they are sensing.