1993 Johnson Evinrude "ET" Electric Outboards Service Manual, P/N 508280, Page 23Get this manual
Battery Installation Install the battery near the motorMount the battery in ventilated case and attach the case to the boatA loose battery can shift in the boat, damaging itself or other equipmentTighten hold-down nuts evenly until the battery is secureIf hold-down nuts are too tight, distortion and damage to the battery case will resultConnect battery cables, making sure clamps are tight on battery posts to ensure good contactApply coat of OMC Triple-Guard grease to exposed areas of battery posts and clamp connectors to retard corrosionBattery Cable Length The following chart shows the minimum cable size for the listed cable lengthsThis is for stranded copper cable without splicesThe maximum length for the largest cable is 20 ft(6,1 m)INotel These specifications do not apply to aluminum battery cablesOMC does not recommend the use of aluminum battery cablesMinimum Recommended Gauge Total Extended Length Model Electric Outboards C02312
110 ft(0,3m)
1115 ft(3,44,6 m)