2004 John Deer Buck Utility ATV 500, 500EX and 500EXT Service Manual, Page 154Get this manual
Temperature below 21C (70F): Hydrometer reading: 1.250 Electrolyte temperature: -1C (30F) Subtract 0.016 SpGrCorrected SpGris 1.234
Temperature above 21C (70F): Hydrometer reading: 1.235 Electrolyte temperature: 38C (100F) Add 0.012 SpGrCorrected SpGris 1.247 Clean the battery casing, caps, cables and battery posts using solution of baking soda and waterRemove corrosion (if so) from battery cable terminals and battery posts using firm wire brushRinse with clear water and dry well
This is the best test of battery condition under starting loadUse load testing device that has an adjustable loadApply load of times the ampere-hour rating of the batteryAt 14 seconds into the test, check battery voltage; if battery is in good condition, it will have at least 10.5 Vdc
Visually inspect battery casing for cracks or other possible damageIf casing is damaged, replace battery and thoroughly clean battery rack with water and baking sodaInspect battery rack mountingInspect battery posts for security of mountingInspect for cracked or damaged battery caps, replace defective caps