Substation Battery Capacity Discharge Test Record

Periodic inspection record for station DC battery constant-current capacity discharge testing, including cell voltages, measured ampere-hour capacity, comparison to rated capacity, and replacement decision when capacity falls below the acceptance threshold.

Inspection Details

• Inspection date and time
• Inspector name and qualification
  Record the technician or engineer performing the test and note qualification if required by site procedure.
• Battery bank identification
  Enter the substation name, battery string ID, nominal DC voltage, and associated equipment designation.
• Reference procedure or standard
  Document the governing SOP, manufacturer procedure, or IEEE-based test method used for the discharge test.
• Test purpose

Test Setup and Conditions

• Battery bank isolated for safe testing
  Verify the battery bank is isolated from normal service in accordance with site lockout-tagout and switching procedures.
• Load bank or discharge equipment rated for test current
  Confirm the discharge load and test instruments are suitable for the planned constant-current test current and duration.
• Ambient temperature at start of test
• Battery electrolyte or cell temperature at start of test
• Test start open-circuit battery voltage

Battery Bank Identification and Rating

• Manufacturer and model
• Rated capacity at specified discharge rate
  Enter the manufacturer's rated ampere-hour capacity at the applicable discharge rate and end voltage.
• Rated discharge rate and duration
  Document the discharge rate basis used for the capacity comparison, such as the site-defined constant-current test rate.
• Acceptance threshold for capacity
  Capacity below this threshold requires a replacement decision and corrective action.

Discharge Test Results

• Constant-current discharge maintained throughout test
  Verify the discharge current remained within the planned test tolerance for the full test period.
• Total discharge time achieved
• Measured ampere-hour capacity
• Measured capacity as a percentage of rated capacity
  Compare measured capacity to the rated capacity using the same discharge basis.
• Lowest cell voltage recorded during discharge
• Any cell reached the minimum allowable voltage
  Flag whether any cell or jar dropped below the site or manufacturer minimum during the test.

Cell Voltage Record

• Cell voltage readings captured for all cells
  Document individual cell or jar voltages at the required test intervals per procedure.
• Cell voltage log attached
  Attach the detailed cell-by-cell voltage sheet, data logger export, or photo of the recorded log.
• Cells with abnormal voltage deviation identified
  Note any cell showing abnormal deviation, weak performance, or evidence of imbalance requiring follow-up.

Disposition, Corrective Action, and Sign-Off

• Battery bank passes capacity acceptance threshold
  Pass only if measured capacity meets or exceeds the acceptance threshold and no critical deficiencies remain.
• Replacement or corrective action required
  Select the disposition based on test results, with replacement required when capacity falls below 90 percent.
• Inspector signature