1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 17Get this manual
MAINTENANCE
Battery Inspection
The battery should be inspected at periodic intervals to ensure proper engine starting capabilityIMPORTANT: Read the safety and maintenance instructions which accompany your battery1Turn off the engine before servicing the battery2Add water as necessary to keep the battery full3Make sure the battery is secure against movement4Battery cable terminals should be clean, tight, and correctly installedPositive to positive and negative to negative5Make sure the battery is equipped with nonconductive shield to prevent accidental shorting of battery terminals
Fuse Replacement Electric Start Models