Mercury Mariner 8/9.9HP 4-Stroke Factory Service Manual, Page 84Get this manual
Battery Charging System (cont 10 Ampere Charging System Electric Start Models Description:
The battery charging system components are the stator lighting coils, rectifierregulator and batteryAlternating current (generated in stator lighting coils) flows to the rectifierregulator, which changes the alternating current to regulated direct current for charging the battery