1994 Johnson/Evinrude "ER" 60 thru 70 outboards Service Manual, Page 233Get this manual
Battery Specifications For each motor provide one battery that is: 12-volt, heavy-duty, designated "marine" Ventedrefillable or maintenance-free Rated 360 CCA (465 MCA) with 90 minutes reserve (50 amp-hrs) Deep-cycle batteries are suitable IF they meet or exceed the minimum CCA requirementsInstalling and Connecting Batteries and Cables Place the battery so it is easily accessible for frequent checking and recharging and in hold-down systemInstall positive cable to positive post and negative cable to negative postr:;] When connecting to the battery, begin by placing large-
surface star washer over the threaded battery post, then stack cables from accessories, then cables from the motorFinish the connection with hex nut, tightened firmly with wrench were supplied with the batteryWing nuts can loosen and cause errant warning horn signals or electrical system damage
fN=J DO NOT use wing nuts on battery connections even if they
[!I Apply OMC Triple-Guard grease to connections"" The battery terminal connections must always be insulatedIf the battery mounting system does not cover the connections, install protective coversThis will help prevent shorting or arcing at the battery terminalsBattery Devices Battery IsolatorsIfthe 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 contain "make-before-break" circuit to protect the engine's charging systemAvoid switching batteries while the engine is running, and turn the switch off only while the engine is stoppedBattery Testing