🔍 Key Concepts

• Lead-acid battery cell condition and how it affects measurable properties • Difference between visual checks, temperature, specific gravity, and voltage tests • Why comparing values between cells is important when troubleshooting

💭 Think About

• Which property of the electrolyte directly reflects the state of charge of a lead-acid battery cell? • Which method allows you to compare all cells under the same conditions to spot one that is weaker than the others? • Is an open-circuit voltage test on small individual cells as precise and diagnostic as another common test used with a hydrometer?

✅ Before You Answer

• Identify which choice uses a hydrometer and what it actually measures • Decide which method gives a quantitative comparison of all cells, not just a rough or indirect indication • Eliminate any options that are mainly supporting checks (good practice) rather than the primary diagnostic test for a weak or dead cell