TUBE 5M6212 - Caterpillar

The battery is often overlooked in many preventive maintenance programs. This is unfortunate because, with a little care, battery life can be substantially extended. Caterpillar® suggests some relatively simple steps to ensure greater reliability and longer battery life.
The most important is to make sure electrolyte levels are checked at appropriate intervals. Standard, or conventional, batteries should be checked every 100 hours. Electrolyte levels should be checked in low maintenance batteries at each 250-hour interval. No acid level check is required or can be performed on the maintenance-free design.
If the electrolyte level is low, add only distilled water to keep possible contaminants out of the battery. While checking the electrolyte, make a few other visual inspections:
1. Is there any indication of damage or corrosion on the battery terminals, the battery box or wiring? If so, clean or replace the necessary components. Cleaning can best be done with a solution of baking soda and water (1 1/2 cups baking soda per gallon of water). Visual inspection could also alert you to the possibility of a cracked battery which could only be identified by corrosion in the battery tray.2. Are the hold-downs tightened correctly? Vibration will destroy a battery faster than anything else.3. Is there debris under the battery? This must be removed when hold-downs are tightened as this can cause holes to be worn in the case and result in loss of electrolyte.4. Are all vent caps correctly in place? Loss of vent caps can pose a potential hazard and permit contamination of the battery.5. Are the alternator belts tight? If not, the battery will not charge correctly and poor performance will result.6. What is the alternator output voltage? Use a voltmeter to check it. This will identify both low charging voltages due to loose fan belt and also high charging voltages which can damage a battery. Alternator charging voltage should be 13.5 to 14.5 volts for a 12 volt system and 27.0 to 29.0 for a 24 volt system.While the maintenance-free batteries do not require electrolyte checks, do steps 1, 2, 3, 5 and 6 every 1,000 hours for maximum battery life.
Another important factor in prolonging battery life is proper storage. Batteries are perishable items and can lose efficiency when not in use. Batteries discharge faster in high temperatures so they should be stored in the coolest place possible. Small, constant electrical current loads like brushless alternators, electronics, clocks, etc., can run a battery down when not in use. If a machine will not be used for 30 days or more, open the disconnect switch or remove the ground (negative) cable from the battery.
The next step is to check the batteries' state of charge. This is called checking the open-circuit voltage. Use a digital volt meter such as 6V7070 Multimeter. An analog meter (moving needle type) is not accurate enough for battery use. Set the voltmeter on the 20-volt DC state and touch the probes to the battery terminals with the engine off. A reading of 12.40 or more