1994 Johnson/Evinrude "ER" 9.9 thru 30 outboards Service Manual, Page 291Get this manual
3Capacity Test Satisfactory capacity tests can be made only when the battery electrolyte equals or exceeds 1.225 specific gravity at 80 (2]0 C) 4Terminal Voltage Test
ill procedures
Use extreme caution during any load testing Improper could overheat battery and cause electrolyte gassingThis might cause an explosive atmosphereaVariable Load High Rate Discharge Tester (Recommended)
I.A12009