Lead-acid batteries convert chemical energy into electrical energy to start the engine and power electrical accessories in a car or truck. A clearer sense of the construction and function of automotive batteries can be helpful when charging, jumpstarting or replacing these parts. Search for the right replacement battery for your vehicle, driving style and the climate where you live. You may also want to ask a customer service associate at the best auto parts store about which batteries are best for a particular make, model and engine type.

Lead-Acid Battery Construction

Conventional car batteries designed to supply the electrical power necessary for starting, lighting and ignition in a vehicle work alongside an alternator to sustain the supply of accessory power and recharge the battery while driving.

Automotive lead-acid batteries are constructed to cause electro-chemical reactions that involve hydrogen, oxygen, lead and sulfur. Most SLI batteries are six-cell designs with a lead and a lead dioxide grid in each cell. Each cell produces around two volts of energy, which amounts to a total of 12 volts.

Chemical to Electrical Energy Conversion

The chemical reaction that takes place in a lead-acid battery to generate electricity takes place in several stages. First, the grids are submerged in sulphuric acid to trigger a reaction in which the lead dioxide plate produces ions that react with the lead grid to give off hydrogen and lead sulfate, thereby producing electrons that generate electricity that flows through the terminals.

Several common issues that can shorten car battery life include continuous low-voltage charging or operation. These conditions often result in acid layering or stratification and sulfation. Periodically test battery levels and resolve any issues that may lower voltage levels.

If a battery is drained of power, the problem may be the alternator. Once the problem is fixed, it may be possible to jump the battery, drive a vehicle a sufficient distance to allow for recharging and sustain a charge. Learn how to check car battery charge levels using a multimeter or by performing a load test.

Recyclable Components

Lead-acid automotive batteries are one of the most commonly recycled components in the world. Up to 99 percent of the materials in each car battery are recyclable through the production process for new batteries and each new battery contains up to 80 percent recycled materials. Ask an auto repair service or a customer service agent at the best auto parts store about how to recycle an old battery.

Reversible Reactions

The chemical reaction that generates power also makes it possible to charge or jumpstart SLI, lead-acid car batteries. Reversing the application of current at the right voltage causes lead and lead dioxide to form on grids. A battery will eventually lose the capacity to support this chemical reaction, in which case battery replacement is necessary.

When you shop for a replacement car battery at the best auto parts store, you can choose from batteries that have a larger cell surface size or more grids per cell for more cold start power, designs with reserve capabilities, or other specialized performance features.