NETA Battery and UPS Systems Testing 1 — Questions and Answers
Question 1: Which battery type allows specific gravity measurement of the electrolyte as a primary acceptance test method?
- Valve-regulated lead-acid (VRLA/AGM)
- Flooded vented lead-acid (Correct answer)
- Sealed nickel-cadmium
- Lithium-ion phosphate
Correct answer: Flooded vented lead-acid
Flooded vented lead-acid batteries have accessible electrolyte, allowing a hydrometer to measure specific gravity as a direct indicator of state of charge.
Question 2: What instrument is used to measure the specific gravity of a battery cell's electrolyte during NETA acceptance testing?
- Megohmmeter
- Clamp-on ammeter
- Hydrometer (Correct answer)
- Digital multimeter
Correct answer: Hydrometer
A hydrometer measures the density of the electrolyte relative to water, which directly correlates to the state of charge in lead-acid battery cells.
Question 3: According to NETA acceptance testing standards, individual float voltage measurements for battery strings should be recorded at which level?
- The entire battery string only
- Each bank (group of 6 cells)
- Each individual cell (Correct answer)
- The charger output terminals only
Correct answer: Each individual cell
NETA requires measuring float voltage at each individual cell to identify weak or failing cells that may not be evident from string-level measurements.
Question 4: What is the primary operational advantage of internal resistance/conductance testing compared to a full capacity discharge test?
- It provides a more accurate measure of remaining battery capacity
- It can be performed online without interrupting the connected load (Correct answer)
- It eliminates the need for float voltage measurement
- It provides specific gravity readings for VRLA batteries
Correct answer: It can be performed online without interrupting the connected load
Internal resistance and conductance testing are non-invasive and can be performed while the battery remains connected to the system, avoiding service interruption.
Question 5: What is the standard end-of-discharge voltage per cell for a 2V nominal lead-acid battery cell during a rated capacity test?
- 2.00 V per cell
- 1.90 V per cell
- 1.75 V per cell (Correct answer)
- 1.50 V per cell
Correct answer: 1.75 V per cell
IEEE 450 and NETA standards define 1.75V per cell as the standard end-of-discharge (final) voltage for lead-acid batteries during a rated capacity test.
Question 6: What minimum percentage of rated capacity must a battery string demonstrate during a NETA acceptance capacity test to be considered acceptable?
- 70%
- 80% (Correct answer)
- 90%
- 95%
Correct answer: 80%
NETA acceptance testing requires batteries to deliver a minimum of 80% of their rated ampere-hour capacity at the specified discharge rate to pass.
Question 7: Which battery type presents the greatest risk of hydrogen gas accumulation during the charging process, requiring adequate ventilation?
- Valve-regulated lead-acid (VRLA/AGM)
- Sealed nickel-cadmium
- Flooded vented lead-acid (Correct answer)
- Lithium-iron phosphate
Correct answer: Flooded vented lead-acid
Flooded vented lead-acid batteries produce and vent hydrogen gas during charging through electrolysis, creating a potential explosion hazard without proper ventilation.
NETA Battery and UPS Systems Testing 1
Which battery type allows specific gravity measurement of the electrolyte as a primary acceptance test method?