Caterpillar (www.caterpillar.com) publishes Cold Weather Recommendations for All Caterpillar Machines, (Excerpted from Operation & Maintenance Manual, SEBU5898-11-01). Further, Caterpillar organizes the document about construction machinery and heavy equipment in cold weather and low temperatures in the following five topical sections of information, operation, maintenance, reference information, and index, including battery recommendations.
In the maintenance section, Caterpillar provides Battery Recommendations and Battery Information, SMCS Code: 1401.* “1U-7297 Coolant/Battery Tester (Fahrenheit) or the 1U-7298 Coolant/Battery Tester (Celsius) are available for testing the condition of the battery fluid and for checking the freezing point of the coolant.” The coolant/battery testers are optical refractometers, which automatically compensate for temperature without adjustment.
Further, Caterpillar highlights how the temperature of the battery affects the battery’s cranking power. Accordingly, a cold battery will not crank the engine, even if it’s warm. On balance, a warm battery will maintain at least 70% of the battery’s cranking power. As a best practice during low temperature events, to preserve the battery’s cranking power, keep batteries warm by storing in a warm environment or by heating the battery compartment.
Cranking power or cold crank amperes (CCA) are the amperes or amps (A) of power required to start the construction machinery, heavy equipment, or other engines in cold weather and low temperatures. Cold crank amperes are a unit of measurement that indicate the amount of amperes a battery can discharge in 30 seconds time at 0°F and maintain 1.2 volts per cell. Ampere-hours measure battery capacity. CCA are different than crank amperes (CA).
Caterpillar warns that when “…an engine is not being operated in cold weather, use a battery charger to keep the battery charged. A full charge prevents the battery from freezing.” Charge all batteries to a corrected specific gravity of 1.250 or above. Further, if a hydrometer is used in place of the recommended refractometer, Caterpillar recommends the following mathematical procedure to correct the hydrometric reading:
At the temperature of 81°F, the specific gravity is 1.220. Subtract .004 from the hydrometric reading for each increment of 10°F below 81°F.
As an alternative option to the mathematical procedure to correct the hydrometric reading, Caterpillar also provides a conversion reference table with corrected readings, Table 9: Corrected Specific Gravity for the Battery at the Specified Temperatures with temperature, actual readings of the hydrometer taken at specific temperatures, and approximate state of charge shown as a percent of full charge.
*SMCS is Service Management Control System, a four-digit code that describes the components of Caterpillar construction machinery and heavy equipment. Each digit of the four digit SMCS code signifies a progressively narrower range of Caterpillar machinery and equipment. For example, the four digit SMCS code 1202 refers to 1000 = engine, 1200 = short block engine, 1202 = crankshaft for the short block engine.
(Source: Caterpillar, Cold Weather Recommendations for All Caterpillar Machines, Excerpted from Operation & Maintenance Manual, SEBU5898-11-01)
(Image: Caterpillar 5R-9120 General Service Line, Dry, Battery)
More in the next blog about weather planning, weather controls™ and weather risk management in the construction industry and built environment…