WARNING: This page is about a different car, the 2002 BMW M Roadster, 2002 BMW M Coupe, 2001 BMW M Roadster, and 2001 BMW M Coupe. However, it is still accessible from the selected car via links, so may be relevant.
REGULATOR E36 SPECIFICATIONS
Regulated voltage at 1500 RPM engine speed / no electrical devices on (at 30 °C to 60 °C at regulator)