1997 Johnson Evinrude "EU" Accessories Service Manual, P/N 507270, Page 60Get this manual
Capacity Test
Satisfactory capacity tests can be made only when the battery electrolyte equals or exceeds 1.225 specific gravity at 80 (27 C)
rn Terminal Voltage TestUse extreme caution during any load testingImproper procedures could overheat battery and cause electrolyte gassingYou might create an explosive atmosphere
1Variable Load High Rate Discharge Tester (Recommended) Connect tester to battery terminal postsDischarge at rate of three times battery ampere hour rating for 15 secondsIf the voltage is 9.6 volts or higher at the end of 15 seconds, the battery has good output capacity2Fixed Resistance Tester This equipment has built-in load for high-rate discharge testingFollow equipment manufacturer's instructions regarding test period and meter readings3Engine Load for Resistance Disconnect charge coil connectors between stator and power packConnect voltmeter across the batteryCrank engine for 15 secondsIf voltage is 9.6 volts or ig her at the end of 15 seconds, the battery has good output capacity12009