Every car contains a battery, and electric cars actually contain two: a main battery that stores the charge used to run the car, and a 12-volt accessory battery, which powers electronic features such as headlights, fans, safety features, power windows, wipers and the car's on-board computer. Whereas the main battery in an electric car is almost always a lithium battery, the accessory battery in all types of cars is usually a 12-volt lead-acid battery. Each type of battery has its own benefits and drawbacks, which factor into its suitability for use in an electric or gas-powered car.
Advantages of Lithium Car Batteries
The key advantage of lithium car batteries is that they are very lightweight, compared to heavier lead-acid batteries. Early electric cars used lead-acid batteries because lithium batteries were not well-developed at the time, but the extra weight meant that these cars were slow and inefficient. The development of lithium batteries allowed electric cars to perform almost as well as conventionally powered vehicles, with much better ranges thanks to the lithium battery's low weight.
Disadvantages of Lithium Car Batteries
The major disadvantage of lithium car batteries is that they cost much more than lead-acid batteries. Although the price of lithium batteries has reduced since the early days of their development, this cost is still significant for auto manufacturers.
Advantages of Lead-Acid Car Batteries
Lead-acid car batteries are much cheaper than lithium batteries, but they are rarely used as the main source of power in modern electric cars due to their extra weight. However, the accessory battery in an electric car is usually a lead-acid battery. This battery is much smaller than the car's main battery, so the extra weight is less important. Also, there are a huge variety of 12-volt lead-acid batteries available for auto manufacturers to buy and use. Relatively few producers offer 12-volt lithium batteries, and the lack of competition means that prices are high.
Disadvantages of Lead-Acid Car Batteries
As well as being heavy, lead-acid car batteries also have environmental drawbacks. Lead is toxic and needs to be handled very carefully to avoid polluting the environment. Lead batteries also have shorter theoretical life spans than lithium batteries, which means that car owners are more likely to need to replace them.
Buying and Replacing Car Batteries
Car owners can replace the 12-volt lead-acid batteries in their vehicles with lithium alternatives. The cost of purchasing the battery can be quite high, but the reduced weight leads to slightly better fuel economy, as well as giving high-performance cars an extra boost. A car owner who needs to replace the 12-volt lead-acid battery might also consider using a lithium battery for environmental reasons. To replace the car battery, a car owner needs to disconnect the cables, remove the old battery, slide the new one into place and reconnect the cables, being careful to connect them to the correct terminals.
Whereas the main battery in an electric car is usually a lithium battery, accessory batteries in many car models are still of the lead-acid variety. Car owners who are prepared to pay a little more for a lithium battery can replace their car's 12-volt battery with a lithium car battery, which will make their vehicle lighter and avoid the environmental problems associated with lead.