1976 Evinrude 40HP outboards Service Manual, Page 75Get this manual
BATTERY TESTS
FLOAT MUST BE FREE
HYDROMETER TEST EYE ON LEVEL WITH LIQUID SURFACE MAKE CORRECTION FOR TEMPERATURE
LOAD TEST DISCHARGE BATTERY AT RATE OF 200 AMPERES FOR 15 SECO DS VOLTAG SHOULD OT DROP BELOW VOLTS (1 VOLT BAT
Figure 7-3Testing Battery The sources of deficiencies noted in the visual inspection should be located and corrected before installation of new batteryBHydrometer This test can only be used when there is sufficient electrolyte above the battery plates to fill the hydrometer tubeDo not, however, take readings immediately after refilling the cells with waterSpecific gravity will vary pOints (.004) with every 10 temperature changeFor each 10 below 80 F, subtract points from hydrometer readingFor each 10 above 80 F, add pOints to hydrometer readingAfter correcting follows: graVityBattery chargingto 80 F, interpret readings as CCapacity Test Satisfactory capacity tests can be made only when the battery electrolyte equals or exceeds 1.225 specific gravity at 80FTerminal Voltage Test 1Variable Load High Rate Discharge Tester (Recommended) Connect tester to battery terminal postsDischarge at rate of three times battery ampere hourrating 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 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 and ground spark plug leadsConnect voltmeter across the batteryCrank engine for 15 secondsIf voltage is 9.6 volts or higher for 12-volt batteries at the end of 15 seconds, the battery has good output capacity