1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 335Get this manual
View the hydrometer with your eye on the same level with the liquid surfaceThe float of the hydrometer must be freeMake correction for the temperatu reo Specific gravity will vary points (0.004) with every 100F (6 C) temperature changeFor each 100F (6 C) below 800F (27 C), subtract points from hydrometer readingFor each 100F (6 C) above 80 (27 C), add points to hydrometer readingAfter correcting to 800F (27 C)interpret readings as follows: aAll cell readings uniform and above 1.225 specific gravityBattery is serviceableMay require chargingbAll cell readings uniform and below 1.225 specific gravityRecharge to full charge and retest 12009
INotel Disconnect positive cable when charging battery cVariation of more than 30 points (0.030) specific gravity between any two cellsBattery condition is questionableRecharge and retest before making replacement3Capacity Test
Satisfactory capacity tests can be made only when the battery electrolyte equals or exceeds 1.225 specific gravity at 80 (27 C)4Terminal Voltage Test aVariable Load High Rate Discharge TesterRecommended) 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 for 12-volt batteries at the end of 15 seconds, the battery has good output capacitybFixed Resistance Tester