🔍 Key Concepts

• Specific gravity as a measure of density compared to fresh water (which is about 1.000) • How the electrolyte in a lead-acid battery changes between charged and discharged states • Use of a hydrometer to check battery condition

💭 Think About

• Think about what happens to the sulfuric acid and water mixture in the battery when it is being charged versus when it is being discharged. • Ask yourself: if we use a hydrometer to check a battery, what information are we usually trying to find out? • Look at the numerical value in option A and compare it to what you would expect for a safe, realistic battery electrolyte specific gravity.

✅ Before You Answer

• Verify whether specific gravity increases, decreases, or stays the same as the battery discharges. • Check if any option incorrectly claims that specific gravity does not change during charging or discharging. • Consider which statement best matches the normal use of specific gravity readings in routine battery maintenance.