2004 Polaris Touring Service Manual, Page 299Get this manual
ELECTRICAL Battery Testing
There are three easy tests which can determine battery conditionWhenever the complaint is related to either the starting or charging systems, the battery should be checked firstLead-acid batteries should be kept at or as near full charge as possibleIf the battery is stored or used in partially charged condition, hard crystal sulfation will form on the plates, reducing their efficiency and possibly ruining the battery
Open Circuit Voltage Test (OCV)
Battery voltage should be checked with digital multitesterReadings of 12.6 or less require further battery testing and charging
Specific Gravity Test
A tool such as the 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 heavymore 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 batteryState Of Charge 100 Charged 75 Charged 50 Charged 25 Charged Charged Conventional Lead-acid 12.60V 12.40V 12.10V 11.90V Less Than 11.80V Conventional Lead-acid 1.265 1.210 1.160 1.120 Less Than 1.100 Yumacron Type 12.70V 12.50V 12.20V 12.0V Less Than 11.9V Yumacron Type 1.275 1.225 1.175 1.135 Less Than 1.115