VALVE GP-RELIEF 3G9895 - Caterpillar

Reference: Special Instruction, SEHS7633-02, "Battery Test Procedure". (IRM), BAT 90-9, Form PELE0178, "New Battery Load Tester".
To correctly test the open circuit voltage and performance during the load test of a battery, a digital voltmeter is required. The first Reference introduced a single test procedure for all batteries including those rated conventional - low maintenance/high output, and those without access to the electrolyte (maintenance free). The new battery test procedure relies on accurate readings to determine a battery's state of charge and performance under load.
Test evaluations indicate some dealers still rely on analog meters (moving needle) found on earlier load testers for voltage readings. However, even if the meters are new, they do not have sufficient accuracy for the new battery test procedure. The end result is often unnecessary replacement of a battery which narrowly "fails" the load test. The chart shows the comparison in accuracy of voltmeters used with Caterpillar battery load testers.
It should be noted that a three percent error in the meter is equal to approximately .3 volts in the load test reading on a 12 volt battery. Abuse or long service life (age) of the measuring device can make the meter reading error even higher. By contrast, the maximum error of the 6V7070 Multimeter is a negligible .025 volts, while the 4C4911 Battery Load Tester is rated at only .01 volts. The 4C4911 Battery Load Tester functions as both a digital voltmeter, and a digital ammeter for testing load settings. Both features will save costs by reducing errors during testing and test set-up time.