In this paper, we present an ultrasonic method for measuring the specific gravity of lead-acid battery electrolyte and study its frequency and temperature characteristics. This method uses an improved frequency scanning ultrasonic pulse echo reflectometer with a two-transducer configuration.
The electrolyte solution in a lead-acid battery expands when warm and contracts when cold. This affects the density and specific gravity of the electrolyte. Hydrometers measure the specific gravity of the electrolyte to determine the state of charge. And changes in temperature can alter our results.
In lead-acid batteries, this is a mixture of distilled water (pure H₂O) and sulfuric acid (H₂SO₄). Sulfuric acid can be dangerous because it is odorless, colorless and strongly acidic so take precautions when working around batteries, especially if the electrolyte is leaking. What is Specific Gravity?
A series of experiments with direct temperature measurement of individual locations within a lead-acid battery uses a calorimeter made of expanded polystyrene to minimize external influences.
The most accurate and direct way to test the state of charge of a battery cell is to determine the specific gravity of the battery electrolyte. The higher the specific gravity of the electrolyte the higher the state of charge. The best way to truly monitor your system over its life is to regularly take and record specific gravity readings.
The hydrometer offers an alternative to measuring SoC of flooded lead acid batteries. Here is how it works: When the lead acid battery accepts charge, the sulfuric acid gets heavier, causing the specific gravity (SG) to increase.
The most accurate way to determine the state of charge of a lead-acid battery is to measure both the voltage and the specific gravity of the battery electrolyte. This gives you a holistic status of the battery. ... The thermometer will measure the …