The power behind electric vehicles

Evan Gower March 7, 2019

The most important technology in the world today is one that gets few headlines and relatively little credit. Yet without it, the gadgets that do dominate the news would fail to exist.

First invented two centuries ago, the humble battery has been a lynchpin for almost every major industrial and cultural revolution since. Now, as we’re on the precipice of the next revolution, it’s battery technology that once again could define our future, and this time there’s a lot more riding on its success than just financial gain. The future of our roads, of society and even our planet relies, in part, on the success of electric cars.

The earliest electric cars, including the iconic 1898 Porsche P1, were powered by lead-acid batteries and the technology has been used in traditional cars since its invention in 1859. Due to their maturity, these batteries are incredibly cheap, making them highly popular. Yet because they’re made from lead electrodes and sulfuric acid, they’re dangerous, toxic, and difficult to recycle. They also have one of the lowest energy densities of common batteries.

During the 1980s, nickel metal hydride batteries came into commercial use. They’re density is markedly higher than lead-acid batteries but they lose charge over time and have relatively slow charging cycles. Hardly ideal for today’s modern EVs. Then came lithium-ion, the battery technology synonymous with today’s electric vehicles. It has more “live” materials compared to nickel metal hydride, making it more volatile. But it’s more reliable, can fit into smaller spaces, withstands larger temperature changes and charges much faster.

There are even variations within lithium-ion. The BMW i3 and Nissan Leaf, for example, use lithium-manganese batteries with a blend of nickel, manganese and cobalt. Tesla’s 90kWh battery uses a mix of nickel, cobalt and aluminium. The latest BMW i3 has a range of 160 miles, the Tesla S 85 pushes this up to a staggering 225 miles.

These batteries work via the flow of lithium ions: the ions move from the positive electrode to the negative, through an electrolyte, as the battery charges and gains power. The battery is charged when the ions stop flowing. As the car uses charge, the ions move the opposite way.

Sadly, despite the significant advancements to electronics within cars, battery technology has not been able to keep apace. Lithium-ion batteries are still expensive to make. Prices are falling, but not in line with consumer or environmental demand. There’s also the issue of charging speeds and infrastructure. Like EV cars themselves, there is a myriad charging options and not all EV chargers and sockets are created equal.

Cars sold in different regions use different types, and there are three different types of connectors that work with a variety of sockets. At its most simple, today’s charging technology comes in three flavours – rapid, fast, and slow. Rapid chargers will “fill up” your electric car to 80% in around 30-60 minutes. Fast chargers typically charge an EV in around four hours, while slow chargers can take up to 12 hours to fully charge an all-electric car. Each charging type additionally uses a number of different ports including Type 1, Type 2 and 3-pin.

Car-wise, European EVs from the likes of Audi, BMW, and Mercedes mostly use Rapid Type 2 ports, yet if you buy a Nissan or Mitsubishi you’ll most likely get a Type 1 connector. Then, of course, there’s Tesla. These EV behemoths use Rapid DC chargers and charge at a staggering 120 kW via Tesla’s proprietary Superchargers.

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If that wasn’t confusing enough, charging points across the UK are run by a variety of energy providers who offer different payment options. At the start of January 2019, there were a little over 19,330 charging points across the UK, some way short of the approximate 50,400 petrol and diesel pumps. Prices for charging your electric car vary, in the same way petrol prices do, yet unlike at standard pumps you can’t necessarily charge your car at all 6,700 locations. It would be like driving into a filling station only to be told it sells the wrong kind of petrol for your car. Choosing a charging point depends on the types of chargers available on-site, your car’s socket, who runs the network, and if you’re already a customer.

The tide is turning, however. By 2020, E.ON plans to have 180 ultra-fast charging stations across Europe. On-par with the charging speeds of Tesla’s Superchargers, these chargers offer up to 150kW, with the option to upgrade to 350kW as more powerful batteries hit the market. The ultra-fast stations can give drivers a 250-mile range in just 20 minutes. E.ON already has 6,000 points across the continent, and the roll-out is expected to include the UK.

Energy providers now offer tariffs designed for EV drivers to charge their cars at home, too. Meanwhile, the Government recently launched a home charge point scheme, with the Energy Saving Trust and the government’s OLEV (Office for Low Emission Vehicles), that helps cover the cost of getting charging points installed in your home. E.ON is fully accredited with the OLEV home charger scheme, with the government committing to making a 75% contribution to every purchase (up to £500 pounds per household/eligible vehicle). Additionally, the On-Street Residential Chargepoint scheme is a £4.5 million pot for local authorities to install public electric charge points.

Plus, E.ON’s scheme extended to fixed tariff energy supply contracts for businesses, installing charging points and providing and managing energy to companies across the UK. In the near future, thanks to schemes like this, you’ll be able charge your car at work, meaning you’ll rarely need to visit a public point anyway.

The next stage will be to reduce charging times, bringing them as close to filling up with petrol as possible, before the introduction of wireless EV battery charging. Mitsubishi and BMW are two major manufacturers developing their own form of so-called inductive charging in which plates on the underside of an electric car charge wirelessly via plates in garages, parking places or driveways. Similar to how wireless phone charging works, in the BMW example, a GroundPad generates a magnetic field which, when it comes within 8cm of a CarPad, generates an electric current that charges the battery. BMW claims its system could fully charge its cars in around three-and-a-half hours. Once this technology matures, entire roads could be transformed into wireless charging pads. There are already electrified roads in Sweden, for instance, that recharge cars and trucks using electric rail embedded into the tarmac. Closer to home, the Department for Transport laid out plans last year to introduce such roads to the UK, as part of a £40 million Government proposal.

The key to unlocking the environmental, and economic benefits of electric cars is to demystify the battery and charging technology and eradicate range anxiety. As interest grows, infrastructure develops and EVs become more popular, the price of the battery technology will drop further. This will further fund research and we may finally stand a chance of living a truly green life.

Learn more about how E.ON is providing electric vehicle charging for business