2003 Polaris ATV Trail Boss 330 Factory Service Manual, Page 199Get this manual
ELECTRICAL
SPECIFIC GRAVITY TEST
NOTE: This test is for Conventional Leadacid batteries onlyMaintenanceFree batteries cannot be openedA tool such as Battery Hydrometer (PN 2870836) can be used to measure electrolyte strength or specific gravityAs the battery goes through the chargedischarge cycle, the electrolyte goes from heavy (more acidic) state at full charge to light (more water) state when dischargedThe hydrometer can measure state of charge and differences between cells in multi-cell batteryReadings of 1.270 or greater should be observed in fully charged batteryDifferences of more than .025 between the lowest and highest cell readings indicate need to replace the battery
LOAD TEST
CAUTION: Remove spark plug high tension leads and connect securely to engine ground before proceedingNOTE: This test can only be performed on engines with electric startersThis test cannot be performed with an engine or starting system that is not working properlyA battery may indicate full charge condition in the OCV test and the specific gravity test, but still may not have the storage capacity necessary to properly function in the electrical systemFor this reason, battery capacity or load test should be conducted whenever poor battery performance is encounteredTo perform this test, hook multitester to the battery in the same manner as was done in the OCV testThe reading should be 12.6 volts or greaterEngage the electric starter and view the registered battery voltage while cranking the engineContinue the test for 15 secondsDuring this cranking period, the observed voltage should not drop below 9.5 voltsIf the beginning voltage is 12.6 volts or higher and the cranking voltage drops below 9.5 volts during the test, replace the battery