1994 Johnson/Evinrude Outboards 40 thru 55 Service Manual, Page 272Get this manual
Battery Devices Battery IsolatorsIf the engine is equipped with fully regulated charging system and it's supporting two or more batteries, use only one of the following isolators (made by Guest Products): One engine to two batteriesModel 2420 One engine to three batteriesModel 2424 Two engines to three batteriesModel 2423 Battery ON-OFF SwitchesAny master on-off switch in the engine's electrical system must containmake-before-break" circuit to protect the engine's charging systemAvoid switching batteries while the engine is runningand turn the switch off only while the engine is stoppedBattery Testing
ill handled with
Battery electrolyte is an acidic solution and should be careIf electrolyte contacts any part of the body, immediately flush the exposed area with water and seek medical attention as soon as possible1Visual Inspection