42 Operator’s Manual Vehicle Maintenance CXU, CHU, GU, TD, MRU and LEU Green dot visible Any green appearance should be interpreted as a green dot and means that the battery is at or above a 65% state of charge and is ready for use or testing. This does not automatically mean that the battery is in good condition. Dark green dot not visible (black dot) This indicates that the battery is below a 65% state of charge and must be charged before testing. A black dot does not mean that the battery is automatically bad.
Clear or light yellow This means that the electrolyte level is below the level of the built-in hydrometer, which may have been caused by tipping of the battery, a cracked case, or overcharging. This battery should be replaced. Charging Charging should be conducted carefully under controlled conditions. Never charge a frozen battery. If a frozen battery is suspected, thaw it in a warm area for several hours before charging. The following chart shows the normal charging times necessary to reach a full charge at 26 °C (80 °F). In colder temperatures, the necessary charging time may increase.
Open Circuit Voltage Battery Spe- cific Grav- ity* State of Charge Charging Time to Full Charge at 80 °F** at 60 amps at 50 amps at 40 amps at 30 amps at 20 amps at 10 amps 12.6 1.265 100% Full Charge 12.4 1.225 75% 15 min. 20 min. 27 min. 35 min. 48 min. 90 min. 12.2 1.190 50% 35 min. 45 min. 55 min. 75 min. 95 min. 180 min. 12.0 1.155 25% 50 min. 65 min. 85 min. 115 min. 145 min. 280 min. 11.8 1.120 0% 65 min. 85 min. 110 min. 150 min. 195 min. 370 min. * Correct for temperature. ** If colder, it will take longer.