DRUM 4F6327 - Caterpillar

Battery gases are an explosive mixture of hydrogen and oxygen. Keep all sparks and flames away from batteries. Charge batteries only in areas with good air movement. Before charging a discharged battery in cold weather, make sure there is no ice in the cells. Charging a battery in this condition can result in an explosion. Always let the ice melt in the cells before charging.
(1) Remove all dirt and corrosion from the battery posts and the top of the battery. Make sure the holes in the vent caps are open and free of dirt because these caps must be installed while the battery is being charged.(2) Check the level of the electrolyte before charging the battery. The electrolyte must be above the plates.(3) If the battery is to be charged in the machine, disconnect the cables from the battery. Remove the cover for the battery and open the battery compartment of the machine. IMPORTANT: The 9S1990 and 1P7400 Battery Charger Testers have a relay for the protection of the charger if the connection to the battery is not correct (a correct connection is the positive lead on the charger to the positive post on the battery, and the negative lead on the charger to the negative post on the battery). If the battery cannot be charged, check the connection of the charger to the battery. Also, if a battery has been discharged too much, there will not be enough voltage in the battery to close the relay in the charger. Connect another battery in parallel with the discharged battery for just enough time to close the relay. (4) Put all switches in the OFF position. Connect BATTERY leads (1) and (2) to the battery posts, red to positive (+) and black to negative (-). (5) Put VOLTAGE SELECTOR switch (3) in the 6 volt position for 6 and 8 volt batteries or in the 12 volt position for 12 volt batteries. Rotate TEST SELECTOR knob (4) counterclockwise to the stop. (6) For fast charging only, set time selector (5) for the desired period of fast charging. Set CHARGE RATE SELECTOR (6) to the rate shown in Special Instruction Form SMHS7633, "BATTERY TEST PROCEDURE". During charging, the battery voltage must not be more than 7.75 volts for a 6 volt battery, 10.4 volts for an 8 volt battery, or 15.5 volts for a 12 volt battery. If battery voltage is more than this in the first three minutes of charging, use the slow charge procedure to charge the battery.(7) For slow charging only, turn TIME SELECTOR (5) to the "O" position. Set the CHARGE RATE SELECTOR (6) to the rate shown in Special Instruction Form SMHS7633, "BATTERY TEST PROCEDURE".Troubleshooting The Battery Charger Tester
(A) Equipment Needed
Volt-Ohm Meter (VOM) Continuity Tester 12 Volt Battery
Always disconnect the power source and the battery before making continuity checks.
(B) Circuit Function
When the BATTERY leads of the battery charger tester are connected to a 6, 8, or 12 volt source, relay RY2 is energized and closes