Which property of a battery is most affected by temperature changes?

The property of a battery that is most affected by temperature changes is specific gravity. Specific gravity is a measure of the concentration of the electrolyte solution in a battery. As temperature increases, the electrolyte becomes less dense, which can lower the specific gravity reading. Conversely, lower temperatures can increase the density of the electrolyte and lead to a higher specific gravity.

Temperature impacts the chemical reactions occurring within the battery, which in turn affects the efficiency of the battery and its ability to hold a charge. For instance, in lead-acid batteries, specific gravity readings can serve as an indicator of the state of charge, since higher specific gravity indicates a higher concentration of sulfuric acid in the electrolyte. These readings can be significantly altered by temperature changes, requiring adjustments for accurate assessment.

While voltage, current, and charge capacity are also influenced by temperature, they are affected in more indirect ways. For example, temperature can affect the internal resistance of the battery and subsequently its performance, but specific gravity provides a direct measurement impacted by the physical properties of the electrolyte. Therefore, specific gravity is usually regarded as the most sensitive property when it comes to temperature variations.