1997 Johnson Evinrude "EU" 40 thru 55 2-Cylinder Service Manual, P/N 507265, Page 265Get this manual
Battery Specifications IT] For each motor provide one battery that is: 12-volt, heavy-duty, designated "marine" Ventedlrefillable or maintenance-free Rated 360 CCA (465 MCA) with 90 minutes reserve or 50 amp-hr
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 post
m When connectingoverthe battery, begin by placing largeto surface starwasher the threaded battery post, then stack
cables from accessories, then cables from the motorFinish the connection with hex nut, tightened firmly with wrench