1974 Johnson 135 HP Outboard Motors Service manual, Page 95Get this manual
7- 2All cell readings uniform and below 1225 specific gravityRecharge to full charge and retestSee note3Variation of more than 30 points (.030) specific gravity between any two cellsBattery condition is questionableRecharge and retest before making replacement FLOAT MUST HYDROMETER TEST EYE ON LEVEL WI TH LIQUID SURFACE MAKE CORRECT ION FOR TEMPERATURE
E;d Note-Discormect positive cable when charging battery CCapacity Test satisfactory capacity tests can be made only when the battery lectrolyte equals or exceeds 1.225 specific gravity at BO FTerminal Voltage Test 1VARIABLE LOAD mGH RATE DISCHARGE TESTER (RECOMMENDED)Cormect tester to batte ry terminal postsDischarge at rate of three times battery ampere hour rating fo 15 secondsU the voltage is 9.6 volts or highe for 12- volt batt eries at the end of 15 sec onds, the battery has good output capacity2FIXED RESISTANCE TESTERThis equipment has built-in load fo high- rate discharge teStingFollow equipment manufacturer's instructions regarding test period and mete adings3ENGINE LOAD FOR RESISTANCEDisconnect and ground spark plug leadsCormect voltmeter across the batteryCrank engine for 15 secondsIf voltage is 9.6 volts or higher for 12-volt batte ries at the end of 15 seconds, the batte ry has good output capacityBATTERY CHARGING Boost charge 12-volt batteries at 50 amperes fo 20 minutes (1000 ampere minutes) the harger will not give this rate, charge for an equal number of ampere minutes at best rate availabl eDO Nar boost batt ry more than this amoWlt for thelight load testIf batteries a.re be fully harged by means of quick charger, the