Electric Cars: Understanding the Terms
Most of us have spent years, even decades, learning how internal combustion engines' powertrains work and how to interpret the figures fossil fuel-consuming cars produce. But now, as the automotive world gradually embraces "the electric car", what new systems do we need to understand – and which are the important figures to know?
BEV, PHEV and hybrid
The Lexus RX 450h is a modern hybrid, no cables required.
These are just abbreviations and descriptions for the types of vehicles that use electric motors and batteries to provide some sort of propulsion.
(B)EV – A fully-electric vehicle (Battery Electric Vehicle) that does not have an internal combustion engine at all. These are vehicles such as the Jaguar I-Pace, Audi e-Tron and VW ID3.
PHEV – Plug-in Hybrid Electric Vehicle. An internal combustion engine teamed with an electric motor-and-battery setup. The plug-in configuration allows for a bigger battery to be installed that allows for more battery-only (pure electric) range. The current electric range on PHEVs is around 30 to 50 km; the fuel-burning combustion engine does most of the work. Examples of such vehicles are the Volvo XC90 T8, Range Rover Sport and Range Rover PHEVs.
Hybrid – These vehicles do not have to be plugged in at all. The electric motor is charged by either regenerative braking or by using the internal combustion engine. Electric-only drive is possible – for very short stints – and is mostly used in very slow driving conditions such as heavy traffic or when pulling away at traffic lights. Examples of this are the Lexus RX 450h, Lexus ES Hybrid and the Toyota Prius.
kWh
Volkswagen is on the EV offensive with multiple cars planned for the next 5 year.
The abbreviation for kilowatt-hour. It’s a unit used to measure battery capacity. Basically, the higher the number, the more range you should have… It’s similar to the size of a fuel tank in a normal car. Jaguar’s I-Pace has a 90-kWh battery with a range of 470 km, the BMW i3 uses a 33-kWh battery with a range of 300 km. It stands to reason that the kerb weight of an EV plays a critical role in the projected optimal range of the vehicle, just as it would in a petrol/diesel car.
It can be a bit confusing: EV chargers and overall power outputs are claimed in kW (especially in South Africa, where we use the metric system).
Regeneration
While electric cars' motors and their ancillaries consume electricity, they're also equipped with technology that enables them to recoup some of those losses. This can be done in 1 of 2 ways: either through harvesting the kinetic energy that is released whenever the braking system slows down the vehicle, or from engine coasting. Both perform the same task of reversing the electric motor, which then recharges the battery. Some systems store the recouped energy in capacitors where it is stored for later use. Braking regeneration is mostly accompanied by brake-by-wire systems that operate the brakes via electrical- rather than mechanical components.
Fast chargers
Fast chargers reduce charging time dramatically if your battery can accept the rate of charge.
A standard charger (which you'd plug into an electrical socket in your house) charges at around 3 kW per hour. A fast charger, such as certain stations on Jaguar’s Powerway and at certain Nissan/BMW/Jaguar dealerships in South Africa, can charge up to 60 kW per hour. Porsche and Tesla reportedly have stations that can recharge at 250 kW per hour (in Europe and the USA). However, most batteries have a limit to how fast you can charge them – for example, if your electric car's system is only rated to accept a maximum input of 22 kW, plugging it into a 60 kW charger will only result in an optimal charge rate of 22 kW.
Inductive charging
Inductive charging for electric vehicles works in much the same way as placing a contemporary smartphone on a charging pad at home or in a such-equipped vehicle. If you'd like to top up an EV in such a manner a charging pad needs to be installed on the floor of a garage or parking bay where you park the vehicle. The EV also has to have a conductive pad on its underside. When the 2 pads are lined up the vehicle will receive a charge. Currently, these are fairly slow chargers (between 3 kW and 20 kW) but they do reduce the need for cables and messy infrastructure. This system is currently being trialled with metered taxis in the UK.
Battery lifecycle
Every battery has a total number of charges it can accept before it begins to deteriorate or produce less range from a full charge than it did when it was new. Lithium batteries, which are used in modern electric cars, are actually pretty good at retaining their capacity for charging, even when they're used daily. Most manufacturers, therefore, offer long warranties (8 years for Jaguar and Volkswagen, to name 2 examples) on EV batteries.
Wall box
A Wall box is installed at home or office and improves the speed at which electric cars can charge.
As mentioned above, when plugged into a home wall socket you can expect a maximum charge of 3 kW. This charging style requires a long time to charge an electric car and it’s not recommended to continuously put that much stress on the socket over a long period of time. If you install a wall box at your house, however, you can increase charging power to 7 kW, which means it will take half the time to charge your electric car compared with using a conventional power socket. Smart wall boxes can even reduce power when load on the national grid is strained and then increase it again when there is less load.
Cable/Plug types
Most electric cars use common plugs and cables to make things easier for buyers.
There is a plethora of cables and plugs that come with EVs or are optionally available. Most EVs sold in Mzansi are equipped with the standard 3-point plug and cable that connects to a household socket. These are often referred to as Mode-2 cables. If you want to charge from a wall box you will require a Mode-3 charging cable or public charging cable. This is also the same cable that is used at AC public charging points like the BMW charging stations. Some stations supply this cable, but it’s probably useful to always have one with you. For DC/fast-charging stations, such as the ones on Jaguar’s Powerway, the cable is supplied, but only certain EVs will accept this form of charge.
Range anxiety
This is the lingering fear that you may run out of battery charge in your electric vehicle and be left stranded. It’s exactly the same as running out of fuel in a petrol/diesel car except that electric cars tend to have comparatively shorter ranges. As charging infrastructure improves and more options become available to charge electric cars, this shouldn’t be so much of an issue. EVs' optimal ranges are rapidly improving; most of them are capable of 300 km+ per charge.
Level 1 charging
Level 1 charging isn’t very common in South Africa, but some houses may only have 120V plug sockets. It is an extremely slow form of charging an EV and adds a meagre 5 km of range for every hour it’s plugged in.
Level 2 charging
As the name suggests, this is a step up from level 1 and takes into account that most South African homes at use 220-240V electricity supply. Theoretically, you could add 35 km of range per hour of charging when connected to a level-2 charger. Wall boxes, if installed at your house (such as the one available from Grid Cars) offer around 7 kW of charge and are classified as level-2 chargers.
Level 3 charging
Jaguar's Powerway makes extensive use of Level-3 fast chargers.
Level-3 chargers (also known as DC chargers) are currently the fastest form of car-charging available. These are the types of chargers fitted at some filling stations, dealerships and shopping centres. The fastest charging stations in South Africa (for the moment) are 60-kW chargers that can add approximately 300 km of range in an hour. Not all EVs can accept DC charging and many PHEVs can’t either, so best to check this before buying.
RFID card
These cards give you access to public chargers. You tap the RFID card against the charger to activate it at which point you can begin charging. The cards need to be topped up with money via EFT payments. Also, note that charging stations have differing electricity rates, you will NOT get Eskom’s rate from a public charger.
EV costing
Want to work out how efficient an EV is? Calculate how much electricity it uses compared with how far it goes. A wall box or public charger will tell you exactly how many units of electricity it used when charging an EV, from there you can multiply the cost of the electricity into the equation (Eskom rates are anywhere between R1.50 and R3 per unit and public chargers are often more than R3 per unit). The size of the battery in the vehicle dictates how much electricity is required to charge it fully (like a fuel tank in a car). When the Jaguar I-Pace's battery is completely flat it will take 90 kWh of charge to "fill it" again. At R3 per unit and 90 units to fill (1 unit is equal to 1 kWh), it would take R270 to fill it.
EV tax in SA
Many countries offer incentives or rebates to make it attractive for buyers to buy electric cars. South Africa, however, does the opposite: there is an extra levy placed on electric cars and the reason for that is unclear. Some suggest it’s "to protect the local manufacturing sector", others say "it would affect the local fuel industry" (if consumers buy less fuel, the government will earn less tax). Electric vehicles are subjected to 25% import duties, but fossil-fuel-fed vehicles, by comparison, incur 18%. Electric vehicles are further subjected to 17% ad valorem (luxury tax duty) because the battery price pushes the overall cost of the vehicle into a luxury threshold. Taxes on electric vehicles and hybrids are 42%.
