- Reduced chemical reaction rate:
The chemical reactions that produce electricity in a car battery slow down at lower temperatures. This is because the molecules in the electrolyte solution, which is responsible for carrying ions between the positive and negative plates, move more slowly. Slower chemical reactions mean less power output, which can make it difficult to start the engine, especially if the battery is already weak.
- Increased internal resistance:
The resistance to the flow of current increases as the temperature drops in a battery. This is because the electrolyte solution becomes more viscous and the ions have more difficulty moving through it. Increased internal resistance means less power output and can put additional strain on the battery.
- Reduced cranking power:
The cold temperatures can affect the ability of the battery to deliver the necessary cranking power to start the engine. This is because the chemical reactions are slower and the internal resistance is higher, which means less power output.
- Sulfation:
Low temperatures can also contribute to the sulfation of the battery plates. Sulfation occurs when lead sulfate crystals form on the surface of the plates, blocking the chemical reactions and reducing the battery's capacity.
- Freezing:
Extreme cold temperatures can also cause the electrolyte solution in the battery to freeze, rendering the battery completely useless.
