How do you use a hydrometer to test a car battery?

Remove the caps from the battery top, squeeze the hydrometer rubber bulb and submerge the tip into the electrolyte. Release the bulb and let some electrolyte to enter the hydrometer container. Check the electrolyte color. You should be able to see through the colorless liquid.

What is the hydrometer reading for a fully charged battery?

1.265
A hydrometer reading of 1.265 indicates a fully charged battery. A 75% charge is 1.225. Approximately 1.190 is half-charged, 25% is 1.155 and 1.120 indicates complete discharge.

What does a hydrometer measure in batteries?

In the case of battery testing, the hydrometer is measuring the specific gravity of the battery’s electrolyte. The higher the acid concentration in the electrolyte, the higher the specific gravity. Based on the specific gravity, the user can determine the state of charge of the battery.

What does the hydrometer read of a fully charged battery?

Again, if a battery is fully charged, your hydrometer should read a specific gravity of 1.265 or more. For flooded lead-acid batteries, the most accurate way of telling its state of charge is using a hydrometer and measuring the electrolyte’s specific gravity.

What is the function of a battery hydrometer?

A battery hydrometer with thermometer (thermohydrometer) measures the temperature-compensated specific gravity and electrolyte temperature . Another automotive use of hydrometers is testing the quality of the antifreeze solution used for engine cooling.

What is a digital hydrometer?

A digital thermo- hygrometer is an electronic instrument that can measure and display the current temperature and relative humidity. It is small enough to be portable or hand-held, and it typically uses batteries for power. The components measure temperature and humidity with changes in electrical resistance,…

How do you check specific gravity of battery?

Measuring the Specific Gravity of a Battery. Specific gravity is measured with a hydrometer. Simply draw the battery acid into the hydrometer so that the float is not touching the sides, top or bottom of the barrel. Take the reading with your eyes level with the surface of the drawn up liquid, and then subtract 0.004 for each 5°C…