The battery in a battery electric vehicle (BEV) is the fuel with which it runs. Whether it’s a pure electric vehicle, only-electric vehicle or an all-electric vehicle, a battery uses the chemical energy that’s stored up in a rechargeable battery pack to make the vehicle run. Being the key component of any electric vehicle (EV), the battery dictates the range of the vehicle, serves as the heaviest electrical component and is its most expensive electrical component.
There are different types of batteries used for EVs, which depend on their chemistry composition. Today, lithium-ion batteries serve as the most common HV batteries used for BEV. These batteries also come in what aptly be called “flavors”, which are metal oxides and phosphates. Among them all, the lithium-ion batteries appear to be more suitable because they’re safer in terms of the thermal and chemical hazard they pose. As these battery cells are getting mass produced, many electric vehicle batteries come in different forms, which include batteries that are a mix of cobalt, manganese, nickel, graphite and other rare metals.
The evolution of batteries today has gone so far already. You can have lithium-titanate and lithium-iron-phosphate batteries as the more ethically-sourced types that don’t need cobalt. They retain importance in the EV market today, along with the growth of battery chemistries that rely only on sodium, magnesium, and lithium-sulfur, mainly because they beat lithium-ion batteries on cost and energy density considerations alone.
It’s interesting that the price today of lithium-ion batteries has significantly declined in costs. Production scale has rendered manufacturers to be more optimal and more developed in the way they produce these EV batteries to achieve a cost-effective production method.
This progress in the production line results, too, in extending the permanent life span of the EVs. Right now most manufacturers are able to offer about 8-year/100,000-mile warranties for their batteries. Brands like Nissan are able to offer a battery capacity loss coverage to as high as 5 years or 60,000 miles.
As EVs undergo rigorous safety testing to meet safety standards, their batteries receive the same attention, too. This ensures that creating the batteries doesn’t result in chemical spillage, battery leaks during a crash and electric shocks resulting from the lack of isolation of the chassis from a high-voltage system.
Moreover, electric-vehicle batteries differ from the standard starting, lighting and ignition (SLI) batteries, which are usually designed to deliver power over sustained periods of time. Batteries for electric vehicles are distinct for their relatively high power-to-weight ratio, specific energy and energy density. Usually, it’s the smaller, lighter batteries that reduce the weight of the vehicle mass size that are used by EVs because they significantly boost performance.
These rechargeable batteries used in EVs include: lead-acid (typically called “flooded, VRLA, or deep cycle), NiCd, nickel-metal hydride, lithium ion and Li-on polymer. The amount of the electricity stored in these batteries is calculated using the ampere hours or coulombs units, with its total energy measured using the watt hours metric.