1978 Johnson 55 HP Outboards Service Manual, Page 98Get this manual
FLOAT MUST BE FREE
HYDROMETER TEST
Install the battery near the motorFor mounting the battery, use Coast Guard approved battery box (available as an OMC accessory) securely fastened to the boatA loose battery may shift in the boat, damaging itself or other equipmentConnect battery cables, making sure clamps are tight on battery posts to insure good contactApply coat of petroleum jelly to exposed areas of the battery posts and clamp connectors to retard corrosion
EYE ON LEVEL WITH LIQUID SURFACE MAKE CORRECTION FOR TEMPERATURE