Introduction to Electric Car Batteries
Demand for electric cars is higher than ever, making up 15.7% of new car registrations in the year so far, up to May 2023 (up from just 0.4% in 2016), according to EV Market Stats 2023. The growth in demand is fuelled by substantial advancements in battery technology, which is leading to ever-increasing driving ranges.
EVs run from the same types of batteries as mobile phones and laptops and are essentially powerful rechargeable batteries. Here we take a look at EV batteries in more detail, helping you make a more informed choice if you’re embarking on a classic Land Rover Series restoration project, like a Defender electric conversion.
What Kind of Batteries Do Electric Cars Use?
As of 2023, the majority of electric cars run on lithium-ion batteries. Other types of batteries exist which could power an EV, although they’re not as common:
- Nickel-Metal Hydride Batteries: Often used in computer and medical equipment, these are more expensive to produce, suffer from high self-discharge, and are prone to heat generation.
- Lead-Acid Batteries: Lead-acid batteries are relatively inexpensive with high power output but perform poorly in cold temperatures and tend to have shorter life cycles than other battery types.
Lithium-ion, AKA Li-on, batteries are the dominant technology used in EVs. Multiple cells are combined into a pack to deliver a high power-to-weight ratio. Li-on batteries perform well under extreme temperatures and have a relatively low self-discharge.
Li-on batteries can produce high quantities of energy per unit mass, which means they can be made smaller than their counterparts, saving space within the EV. For Landy conversions to electric, size matters – classic car chassis were not designed for batteries.
Exploring Battery Chemistry
Electric car batteries are made up of four key EV components:
- A cathode is a type of electrode (electric conductor), where electricity flows out.
- The anode is the opposite electrode, where electricity flows in.
- The liquid electrolyte is a solution that moves lithium ions smoothly.
- A separator is in place to prevent short circuits.
When the battery is charging, the electric current from the charger separates electrons from lithium atoms. The electrons flow around an outside circuit. Meanwhile, the ionised lithium atoms flow through the electrolyte. The lithium atoms are reunited with their electrons at the anode.
When the battery discharges, the reaction happens in reverse. As the electrons flow through the outside circuit, they power the car’s motor.
Battery Capacity and Range
The amount of energy stored in an EV car battery is measured in kilowatt-hours (kWh). The greater the kWh, the larger the battery capacity and the more miles the car can travel.
Much the same as traditional fuel cars, electric cars come with different-sized batteries and consequently, different ranges. Depending on the battery size, a modern EV can travel between 150-300 miles.
Battery Management Systems
A core safety and performance component for an EV is its battery management system (BMS). These devices are installed to keep the battery running within predefined safety parameters.
A typical BMS can:
- Monitor the battery’s State of Health (SOH), collecting data about voltage, temperature, state of charge, and much more.
- Optimise the battery’s thermal temperature.
A key function of the BMS is to prevent the battery from being placed in an extreme state of charge. It stops the battery from being charged to 100% all the time, which can improve overall longevity.
Whether you’re driving a small EV run around or a Land Rover electric conversion, you want to enjoy your vehicle! That means avoiding the dreaded range anxiety, which some EV drivers experience.
The UK government is committed to developing the UK’s charging infrastructure to support the growing demand for electric cars. Consequently, it’s already easier to find a charge point now than it was even at the beginning of the year.
As of 1st April 2023, there are 40,150 public EV charging devices, around 19% of which are “rapid” devices. This represents an increase of 8% since 1st January 2023. According to His Majesty’s Government Data, a driver is never more than 25 miles away from a rapid charge point in England.
Over 80% of public chargers are either classified as “destination” chargers or “on-street” chargers. This means you should be able to conveniently find a charger in places like shopping centres, leisure centres, car parks, or residential streets.
Factors Affecting the Longevity of Electric Car Batteries
Electric car batteries naturally degrade over a period of several years, storing less charge as they age. Most car manufacturers offer a warranty of 5-8 years, but current estimates suggest EV batteries will have a lifespan of 10-20 years.
To preserve lifespan, EV cars are fitted with cooling systems and the batteries are buffered so that the driver cannot draw down the full amount of power stored.
You can help to maintain your battery’s longevity by:
- Driving efficiently – accelerating gently and maintaining consistent speeds
- Managing temperature – parking in the shade or plugging in when it’s hot
- Charge slowly – avoid using rapid chargers for every charge
Innovations Driving the Evolution of Electric Cars
EVs are no longer the realm of science fiction, they’re a mainstream option that continue to evolve:
- Cheaper: EV cars are more affordable, but still remain more expensive than their fuel-powered equivalents. The cost point is helping to push the technology forwards, bringing the cost of batteries down.
- Range: Innovations like lithium-ion phosphate technology not only make battery production more cost effective, it’s also pushing up the usable range. We may eventually see EV ranges of 500+ miles.
- Recycling: As the first generation of EV batteries come toward the end of their useful lifespan, we’ll be faced with the question of what to do with the batteries. One option is to incorporate the remaining charge in a battery energy storage system to power homes alongside solar or wind power.
The Promising Future of Electric Vehicle Energy Storage
The world’s governments are under pressure to hit Net Zero targets, which means reducing our dependence on fossil fuels. The demand for electric cars shows that they’re a viable alternative to traditional vehicles, but more improvements are needed around performance for people to fully embrace the technology.
The next phase in EVs could be solid-state batteries. Working in much the same way as lithium ion batteries, the liquid electrolyte is replaced with a solid electrolyte. The outcome is a smaller, lighter, safer battery.
The classic Land Rover Series we convert at Electric Car Converts are fitted with carefully-chosen batteries to suit your car’s chassis, making efficient use of the space to deliver maximum range. Our specialist team are constantly monitoring developments in the electrification field, ensuring that your electric Landy will be retrofitted with the best technology available.
If you are looking to convert your classic Land Rover of any time into electric, get in touch and we’ll help you future-proof your classic for the next generation!
Reviewed by Barnaby Birkbeck, Founder & Head Electrical Engineer, in 2023.