Car Battery – Automotive Battery
A car or automotive battery is a rechargeable battery used to start a motor vehicle. It is also known as the SLI battery. The term SLI refers to starting, lighting, and ignition. Its main purpose is to provide an electric current to the electric-powered starting motor, which in turn starts the chemically-powered internal combustion engine that actually propels the vehicle. Once the engine is running, power for the car’s electrical systems is still supplied by the battery, with the alternator charging the battery as demands increase or decrease.
Car batteries are designed to deliver the maximum current in a short space of time, keeping the voltage constant, therefore, they have a very low internal resistance. These batteries have a good life under shallow-cycle conditions but have a very poor lifetime under deep cycling (around 12-15 cycles). Current discharges might be with strong temperature changes, which is why the weight, design, and shape are characteristic. These types of batteries are usually frequent for starting cars and all types of diesel and gasoline vehicles.
Advantages and Disadvantages of Car Batteries
Advantages:
A car battery is relatively heavy for the amount of electrical energy it can supply. Its low manufacturing cost and its high surge current levels make it common where its capacity (over approximately 10 Ah) is more important than weight and handling issues.
Compared to modern rechargeable batteries, car batteries have relatively low energy density. Despite this, their ability to supply high surge currents means that the cells have a relatively large power-to-weight ratio. It has become the standard battery for the automotive industry and is commonly used as the power source for starting, lighting, and ignition (SLI) in cars, where it is able to deliver a very high peak current (let’s say about 450 amperes).
Disadvantages:
The disadvantage of this battery chemistry is that it is very sensitive to deep cycling compared to other battery systems, and due to the high density of lead, the specific energy of the batteries is quite low. Charging a lead acid battery system is slow, and it can take up to 16 hours for a full charge. It also requires a current and voltage limiting algorithm, hence limiting the charging current and power. If the charging current is too high, it will cause sulfation which may degrade the performance and cycle life of the battery. Furthermore, the charging voltage must be regulated as the maximum voltage applied is limited by the ambient temperature due to the risk of hydrogen gas generation.
