Automotive batteries are power storage component of your vehicle. It converts chemical energy to electrical energy upon ignition to start your engine and power your accessories.
Keeping it in good shape helps you avoid costly repairs and maintain safe driving conditions. Pop the hood to visually inspect the battery and keep it clean of corrosion.
Cells
A car battery is a collection of electrochemical cells. It is filled with a solution of sulfuric acid in each cell (the electrolyte). The chemicals on the positive and negative plates create ions that move freely through the electrolyte. The ions generate current, which powers the car’s electrical systems.
A typical automobile battery contains six lead storage cells that produce 2.1 volts each for a total voltage of 6 x 2.1 = 12 volts. These cells are connected in series, end to end and – to +.
The car battery’s chemical action can be reversed by connecting it to an external DC voltage (charging). This recharges the internal electrodes and electrolyte. The car battery’s case protects the contents from spillage or injury. The liquid inside — the electrolyte — is toxic and must be kept away from people or animals. Early car batteries used hard rubber cases and wooden plate separators. Now, most are made of plastic and feature heavy straps to link the positive and negative cells.
Separator
A battery separator is one of the most important parts of a lithium-ion battery. It’s responsible for the battery’s efficiency and safety. It shouldn’t react with either the anode or cathode electrodes, and it should enable safe passage of lithium ions between them.
In addition, it needs to be impregnated with the liquid electrolyte and have an appropriate pore size, porosity, and tortuosity. It also needs to be chemically stable and have sufficient mechanical strength.
During charging, the separator allows the movement of lithium ions from the anode to the cathode. When the battery is discharging, it prevents ions from crossing back to the anode. This is what creates the electrical potential difference – or voltage – that charges your electronic device. Companies are constantly improving the performance of separators. For example, they’re attaching silica nanoparticles to their separators’ pore walls. This boosts wettability, increases thermal stability, and improves the rate at which the electrolyte wicks through it.
Casing
A battery casing is a container that directly encloses a single battery cell. It can be made from a variety of materials, including metals for high durability and plastics for lightweight construction. The case is designed to withstand harsh conditions like impact, vibration and thermal abuse without damaging the cells inside.
The case is also designed to manage and dissipate heat to prevent overheating. It also provides electrical insulation to protect against short circuits and chemical protection that resists corrosion and other chemical reactions.
The casing is usually made from a polypropylene resin that encloses the battery cells and conductive elements. The polypropylene is a thermoplastic material that offers many advantages over hard rubber cases, such as higher strength, better shock resistance and the ability to be welded thermally. It is also thinner than hard rubber casings, which helps to reduce weight and cost. Some batteries are designed with a built-in hydrometer window to allow for periodic topping up of water to compensate for loss from electrolysis and evaporation.
Terminals
Battery terminals are the gateway for electricity to flow through your car’s electrical system. Thick black wires connect the negative terminal to a chassis ground and complete circuits that power the engine and other components. A red wire connects the positive terminal to the rest of the electrical system, including radio and accessories.
Most lead acid automotive batteries feature “top post” terminals that look like truncated cones with slightly different diameters to help prevent incorrect polarity connections. Marine batteries may use L terminals or faston tabs designed for a wing nut connection, and some specialized battery designs utilize other terminal types.
If your vehicle’s battery terminals have a lot of corrosion, they might need to be replaced. R&J Batteries stocks a wide variety of replacement battery terminal clamps at our local stores, available for all types and brands of batteries. Always wear gloves and eye protection when working on a car battery because it contains sulfuric acid. If this fluid comes into contact with your skin or eyes, flush immediately with water and seek medical attention.