Electric car batteries are the most expensive single component in an electric car.
It’s high price tag means that electric cars are more expensive than other fuel types, which is slowing down mass EV adoption.
R&D labs around the world are driven to experiment with new battery chemistries and technologies to facilitate a faster, smoother transition to net zero.
In this article, we discuss what the main types of electric car battery are currently, both in production and in development, and the benefits and drawbacks of each.
We know what you’re thinking: with the rate at which new electric car battery technologies are being developed, surely you’d be better off waiting for the next big generational ‘leap’? - not at all! With electric car leasing, you can always have the latest and greatest tech. If you want the best prices to match, be sure to compare electric car lease deals with Lease Fetcher!
What are the different types of electric car batteries?
Having established that there are a wide variety of factors that EV manufacturers must take into account when deciding on an appropriate battery technology, we can now turn to the available battery chemistries and their properties.
Lithium-ion batteries are the most popular. Without going into too much detail, they discharge and recharge as the electrolyte carries positively charged lithium ions from the anode to the cathode, and vice versa. However, the materials used in the cathode can vary between lithium-ion batteries.
LFP, NMC, and NCA are three different sub-chemistries of Lithium-ion batteries. LFP uses Lithium-phosphate as cathode material; NMC uses Lithium, Manganese, and Cobalt; and NCA uses Nickel, Cobalt and Aluminium.
Benefits of Lithium-ion batteries:
- Cheaper to produce than NMC and NCA batteries.
- Longer lifespan - deliver 2,500-3,000 full charge/discharge cycles compared to 1,000 for NMC batteries.
- Generate less heat during charging so it can sustain a higher rate of power longer into the charge curve, leading to faster charge without battery damage.
- Can be charged to 100% with little battery damage as it helps to calibrate the battery and provide more accurate range estimates - Model 3 owners with an LFP battery are advised to keep the charge limit set to 100%
Last year, Tesla actually offered its Model 3 customers in America a choice between an NCA or an LFP battery. The NCA battery was 117kg lighter and offered 10 miles more range, but had a much longer lead time. However, Tesla also recommends that the NCA battery variant is only charged to 90% of its capacity. In other words, if you plan to regularly use the full range, the LFP may still be the better option.
Nickel-metal hydride batteries (abbreviated to NiMH) are the only real alternative to lithium-ion batteries that is currently on the market, though they are usually found in hybrid electric vehicles (mostly Toyota) as opposed to pure electric vehicles.
The main reason for this is that the energy density of NiMH batteries is as much as 40% lower than lithium-ion batteries.
Benefits of Nickel-metal hydride batteries
- Much cheaper to manufacture than lithium-ion batteries
- Car battery recycling is also much easier.
- NiMH batteries can also withstand much harsher weather conditions, whether that’s freezing winters or blazing hot summers.
Lithium-ion batteries are preferred over NiMH batteries, but in colder climates, NiMH are best, and they help to push down the currently higher cost of electric cars.
So we’ve explored the main electric car battery types on the market right now, but what about the electric car batteries of the future? Let’s take a look at some of the more promising developments:
Solid-state batteries are widely touted to be the next big breakthrough in battery technology. These wouldn’t replace lithium-ion as such, but would use a solid rather than a liquid electrolyte.
When the technology is perfected, there are a number of benefits we can expect to see from solid state batteries.
Solid state batteries would be lighter and more compact than current batteries with a liquid electrolyte, which means the weight of the car could be reduced or the storage capacity increased.
Solid state batteries would also be more resistant to fire in the event that they are punctured or impacted, as they lack the flammable liquid electrolyte.
Maximum charging speeds would also be greatly improved, with a full recharge achieved in a little over 10 minutes. It’s also likely that they’ll have a much longer lifespan. Researchers at Harvard have already designed a lithium-metal solid-state battery that can be charged and discharged at least 10,000 times at a high current density.
Supercapacitors are electric storage devices which can be recharged very quickly and release a large amount of power. They store energy electrostatically rather than chemically, like a battery.
They cannot yet compete with Lithium-ion batteries because they have a much smaller capacity to store energy. However, they have far superior lifespans.
Are all electric car batteries the same?
No! Just as conventionally-fuelled cars have large or small fuel tanks, EV battery packs come in different sizes. Instead of litres of fuel, their capacity is measured in kilowatt hours (kWh). Generally speaking, the larger the capacity in kWh, the longer the range of the EV.
The size of EV batteries isn’t the only difference. The chemical composition of electric car batteries can vary between cars and manufacturers. Different chemical compositions, or ‘battery chemistries’, can provide unique advantages.
Below are some of the main factors that electric car manufacturers need to take into consideration when choosing an EV battery chemistry:
The majority of electric car batteries use lithium-ion technology, similar to what we find in our phones and laptops.
While the price of lithium-ion batteries has fallen by as much as 97% since 1991, EV batteries remain prohibitively expensive. But new battery chemistries such as lithium iron phosphate, which use cheaper raw materials, could soon change that.
- Energy density
When the Nissan Leaf launched over a decade ago, the term ‘range anxiety’ reflected a near-perpetual fear of running out of charge in a place with no charge points.
Fortunately, the situation has improved greatly since then. EV owners are less concerned about how often they have to charge their electric cars. EV batteries now have much longer range, and as our handy charging point map demonstrates, charging stations are now near-ubiquitous.
Unfortunately, slow charging speeds can make longer journeys a nightmare in all but the biggest EVs. In most cases, it’s simply not possible to add a bigger battery.
Further range increases will require more energy dense batteries (enabled by different battery chemistries), or innovations like Tesla’s ‘structural battery’, which relies on the battery as a key structural component, allowing for weight saving elsewhere.
- Operating temperatures
One of the major drawbacks of EVs over petrol or diesel cars is that their range, charging speed, and lifespan can be negatively impacted by the ambient temperature.
Cold temperatures can significantly reduce your range, and you’ll need to pre-warm the battery and charging socket for optimal charging speeds. However, hot temperatures are much worse for battery longevity.
Obviously, this can present some issues if you live in particularly hot or cold climates. One of the promises of new battery chemistries is a greater range of optimal operating temperatures.
- Maximum charging speeds
The rate at which a battery can charge or discharge current is called its ‘C rate’. ‘1C’ means that the battery can be fully charged or discharged in an hour; ‘2C’, in 30 minutes; ‘5C’ in 12 minutes; and so on.
All charging and discharging of batteries generates internal heat, which increases with the amount of current supplied. When a battery is built to allow higher C-rates than usual, manufacturers must take into account this increased heating.
Manufacturers can limit the impact this has on the battery using a Battery Management System (BMS) which monitors the temperature of the battery and limits the ‘C rate’ to increase the lifespan of the battery.
It is hoped that with new battery technologies, such as ‘solid state batteries’, manufacturers will be able to enable higher C rates and reduce the length of time it takes to charge an electric car.
All batteries are rated for a number of ‘charge cycles’: the number of times a battery can discharge 100% of its battery capacity.
The estimated number of charge cycles can vary considerably between different battery chemistries, with lithium iron phosphate (LFP) batteries expected to last considerably longer than the more widespread nickel-manganese-cobalt (NMC) batteries.
Do EVs have auxiliary batteries?
Just like their petrol and diesel-powered counterparts, EVs have an additional auxiliary battery to power certain on-board electrical equipment, like radios and lights.
In most cases, auxiliary batteries in EVs are just like the standard 12v lead acid batteries you find in conventionally-fuelled cars.
For many EV owners, this solution has proved frustrating, with Tesla owners needing to replace their lead acid batteries every 2-4 years.
The new lithium-ion auxiliary battery is smaller and lighter, and may be able to charge and discharge up to 2,000 cycles while retaining 80% state of health. In theory, the new auxiliary battery could last as long as the car, or at least match up with the lifecycle of the main battery pack.
Tesla is actively considering moving to a 48v auxiliary battery in future models. A 48v system would bring further improvements, allowing thinner wires to be used throughout the car, making it cheaper and lighter.
What are the best batteries for electric cars?
Lithium-ion batteries are currently the most widely-used - and for good reason. They offer high energy density and the cost to produce lithium-ion batteries has declined drastically over the last 30 years.
However, when it comes to lithium-ion sub-chemistries, LFP may come out on top. Although less energy dense than NMC or NCA, it is cheaper and has a longer lifespan.
Many are betting on solid state lithium-ion batteries to replace the current liquid electrolyte lithium-ion batteries. Once perfected, these could offer greater energy density, longer lifespans, and faster charging capabilities.
Getting electric car batteries right is the key to mass adoption. EV batteries have come a long way since the launch of the Nissan Leaf, and there are plenty of exciting developments on the horizon.
But if battery technology is changing so quickly, it is only reasonable to ask: ‘should I buy an EV now, or wait?’
If you’re serious about cutting costs (and your carbon footprint) then we think buying an electric car is a no-brainer (you can decide for yourself with our list of electric car pros and cons). And with an electric car lease, you can easily upgrade to the latest battery technology when it becomes available.
If you agree, be sure to compare electric car lease deals with Lease Fetcher for the best possible prices!