🔍 Key Concepts

• Differences between lead-acid and nickel-cadmium (Ni-Cad) battery chemistry • What electrolyte specific gravity does and does NOT indicate for different battery types • How voltage under load relates to a battery’s true capacity

💭 Think About

• Think about which battery type uses changes in electrolyte density to show how charged it is. Does a nickel-cadmium battery’s electrolyte change the same way as a lead-acid battery? • Consider which measurement most directly reflects the battery’s ability to deliver power over time: current, voltage, resistance, or electrolyte density? • Ask yourself whether measuring resistance on a high ohms scale tells you anything useful about a battery’s state of charge.

✅ Before You Answer

• Verify whether Ni-Cad electrolyte specific gravity changes significantly with state of charge • Check which test method is commonly recommended in manufacturer maintenance instructions for Ni-Cad batteries • Confirm whether open-circuit voltage vs. voltage under load is a more reliable indicator of usable capacity for this battery type