Method For Judging The Quality Of UPS Batteries

When it comes to assessing the quality of a battery, most average users do not have a dedicated battery measuring instrument at their disposal. Instead, they rely on a multimeter and some practical techniques. Here is a summary of how to judge the battery's quality during maintenance:

1. Visual Inspection: Start by examining the battery's appearance for any signs of deformation, protrusion, leakage, rupture, burning, or oxide leakage at screw connections.

2. On Load Measurement: If no abnormalities are observed in the battery's appearance, you can test its performance by operating the UPS in battery mode with a specific load. If the discharge time is significantly shorter than normal, and even after an 8-hour charging cycle, the backup time fails to restore to its usual duration, it indicates battery aging.

3. Multimeter Measurement:

A. Battery Discharge Mode: In this mode, measure the voltage of each terminal in the battery pack. If any of the battery terminal voltages deviate significantly from the nominal voltage (typically 12V/cell), it suggests battery aging.

B. Mains Mode: Measure the charging voltage at each terminal of the battery pack. If the voltage of one or more batteries significantly differs from the others, it indicates battery aging.

C. Total Voltage Measurement: Measure the total voltage of the battery pack. If the total voltage is considerably lower than the nominal value (considering a C1K battery pack with a nominal value of 36V), and it fails to return to normal even after 8 hours of charging, it suggests battery aging. Even if it does reach the normal value, the discharge time might still fall short of the expected duration.

D. Battery Startup Measurement: Before turning on the UPS and without connecting to the mains power supply, measure the total voltage of the battery pack using a multimeter. For instance, in the case of C1K, the voltage may range between 36V-40V, indicating a normal value. Keep an eye on the multimeter indicator and then proceed to switch on the power. If the total battery voltage immediately drops below 30V or even plummets to a few volts, leading the UPS to shut down automatically, and if the voltage promptly returns to its original value after shutdown, then it suggests battery aging.

By following these techniques, users can assess the quality and condition of their batteries without needing specialized battery measuring instruments.