Lead-Acid Battery Periodic Inspection & Maintenance Guide

Storage batteries are the core backup power supply for power stations, UPS systems, communication base stations and industrial power distribution rooms. Regular standardized periodic testing and maintenance can effectively extend battery service life, avoid sudden power failure risks, reduce equipment replacement costs, and guarantee stable emergency power supply. This article sorts out unified inspection standards, operation specifications and targeted maintenance solutions for monthly, quarterly and annual battery maintenance work, which can be used as on-site operation manuals for electrical maintenance engineers.

1. Monthly Routine Battery Maintenance Items

Monthly maintenance focuses on appearance cleaning, physical integrity inspection, connection tightness and floating charge voltage detection, which belongs to daily regular patrol work with low operation difficulty and high fault prevention efficiency.

1.1 Battery Surface & Battery Room Cleaning

Inspection Standard: Keep the whole battery surface and battery compartment dry, dust-free and free of conductive pollutants.

Maintenance Operation: Wipe the battery shell with a damp soft cloth or clean dust with a soft brush regularly to remove accumulated dust, acid mist and conductive impurities on the surface.

1.2 Battery Appearance Shell Inspection

Inspection Standard: The battery casing must be smooth without bulging, acid leakage or liquid overflow traces.

Maintenance Operation: If swelling, crack or acid leakage is found on any single cell, replace the faulty battery immediately to prevent corrosion of adjacent batteries and circuit short-circuit hazards.

1.3 Connection Bar Inspection

Inspection Standard: All battery connecting bars and terminal lugs have no loose bolts, rust, white sulfate corrosion or oxidation.

Maintenance Operation: For corroded connection positions, completely polish and remove rust spots first, then evenly coat conductive grease on terminals and connecting bars to isolate air and prevent secondary oxidation.

1.4 Single Cell Voltage Test (Under Floating Charge State)

Inspection Standard of Voltage Deviation:

2V single cell battery: Voltage deviation ≤ 60mV

6V combined battery: Voltage deviation ≤ 180mV

12V combined battery: Voltage deviation ≤ 360mV

Maintenance Operation: When the voltage difference between single cells exceeds the standard range, perform multiple charge-discharge cycles on the whole battery pack to balance cell voltage and eliminate inconsistency.

2. Quarterly Battery Maintenance Items

Quarterly testing adds DC power switching simulation and internal resistance testing on the basis of monthly patrols, to verify the actual discharge performance and internal health of the battery pack.

2.1 DC Power Supply Switching Test

Inspection Standard: Cut off AC input power or lower the floating charge voltage of the switching power supply, the storage battery pack shall independently supply power stably for 10–20 minutes without abnormal voltage drop.

Maintenance Operation: Monitor battery charging current limiting status, automatic switching between equalizing charge and floating charge mode during the whole discharge simulation process to confirm the power supply control system works normally.

2.2 Battery Internal Resistance Test

Inspection Standard: Mark and record all single cells whose internal resistance is higher than the average internal resistance of the whole battery string.

Maintenance Operation: Focus on checking whether the fastening bolts and connecting bars of high-internal-resistance batteries are loose or oxidized; retighten terminals and reapply conductive grease if looseness exists.

3. Annual Deep Capacity Testing & Maintenance Standards

Annual full-capacity discharge test is the most comprehensive health assessment for battery packs, used to judge the actual available capacity and determine whether single cells or the whole group need replacement.

3.1 Capacity Calibration Discharge Test

Inspection Standard: Discharge the battery pack with current no less than 10-hour rate, analyze the actual residual capacity of each cell via professional discharge tester.

Maintenance Operation: If the test result shows insufficient single cell capacity, conduct on-site detailed cause analysis and submit the test report to management for follow-up disposal arrangement.

3.2 Full Capacity Discharge Test

Inspection Standard: Discharge the battery with current not exceeding 10-hour rate; terminate discharge immediately once any single cell voltage drops to 1.8V.

Maintenance Disposal Rules:

Replace or activate single cells with residual capacity less than 80%;

Apply for scrapping of the entire battery pack if more than one cell has residual capacity below 60%.