Mercury Mariner 25HP 4-Stroke Outboard Service Manual 1997, Page 77Get this manual
Battery Charging System 15 Ampere Charging System Description:
The battery charging system components are the
stator battery charge coils, regulator and batteryAlternating current (generated in battery charge coils) flows to the regulator, which changes the alternating current to regulated direct current for charging the batteryaStator