Engine: Electricity

1. A Measuring the specific gravity of each cell with a hydrometer.
2. B Measuring the battery voltage with a digital voltmeter during charge or discharge.
3. C Measuring the battery voltage with a solenoid type voltage tester during charge or discharge.
4. D Measuring the temperature-corrected specific gravity of each cell with a hydrometer and thermometer.

Tip: press A-D to answer