Cutting Through The Confusion When It Comes To Charging Your EV

Everything you need to know about charging (speeds, types, levels)

We all know that when you buy, own or drive a BEV (an EV 100% powered by battery), you will have to charge the thing. You might think it’s a simple proposition… and it is. You plug your EV into a power source and let the electrons flow. But there are quite a few other things you have to consider.

Let’s look at the intricacies of charging, charging paraphernalia and accessories (called EVSE or EV service equipment), charging speeds, battery levels… and more. At the end of this article, you should understand the complexities and limitations of powering your EV, and how to efficiently charge your car.

Types and Levels

Both ‘Types’ and ‘Levels’ are common terms used when referring to charging your EV. Knowing the difference will sort any EV debutant out. It can get a little confusing when you add CCS to the mix, but let’s start at the beginning.

Types

'Type’ refers to the fitting of the charging equipment and is part of your EVSE or Electric Vehicle Supply Equipment.

The fittings and charging cables are what you plug into the car and charger. There are several available and they depend on your car and where you live. The main ones are Type 1*, Type 2, CCS-Type 1 and CCS-Type 2 (the bit that’s a little confusing!), and of lesser importance, there’s also CHAdeMO.

*In the US, the Type 1 fitting used also has the suffix J1772 but this is often abbreviated to Type 1.

Take a look at the diagram which shows you the fittings and what each is adapted to.

Here are the main distinctions for Types 1 and 2:

Types 1 and 2 are suited to AC charging only. (AC =  Alternating Current – the same type of electricity that powers your home. “Alternating” refers to the frequency at which the current alternates its direction. This frequency is usually 50Hz or 60Hz, depending on the country)

Therefore home charging is always only AC.

• Type 1 has 5 pins. Up to 7.4kW.
• Type 2 has 7 pins. Up to 43kW.

These connectors tend to be used at home and connect your car to a plug outlet or wall charger.

Straight away you can see that Type 1 can only have a maximum charge input of 7.4kW.

Here are the main distinctions for CCS fittings:

CCS refers to Combined Charging System, where Type 1 and Type 2 fittings are combined with an extra 2-pin connector to now be referred to as CCS-Type 1 and CCS-Type 2.

The two additional direct current (DC) contacts allow for high-power DC fast charging.

DC = Direct Current, not used in the home (except in small batteries, eg. Flashlights), but in higher power contexts.

A CCS-Type fitting enables the provision of power at up to 350 kilowatts (or higher).

CCS is the emergent global standard for charging electric vehicles

Use CCS fittings for public chargers for both AC (slow) or DC (faster speeds).

CHAdeMO type fittings

CHAdeMO is a type of EVSE found in Asian cars, and used in the oldest EVs such as the Nissan Leaf.

This multi-purpose fitting type on its own allows for AC charging, high DC charging capacity as well as bidirectional charging. But—as standardization of EVSE occurs—CHAdeMO is falling out of use in USA, EU and Australia.

Important notes to remember

If you have one of the first EVs such as a Nissan Leaf, they have an old-type CHAdeMO fitting and charging those outside of the home is harder now because the market is moving towards the Type 1, 2 (and CCS) fittings.

For very fast (DC) charging, and to accept speeds of above 43kW (and up to 350+kW), you need a special plug with 2 extra pins below the Type 1 or 2 plug ( CCS-Type 1, or CCS-Type 2).

In summary:

• Type 1 (also called Type 1-J1772): AC, single-phase plug, home use, US and Asia. It has 5 pins. To 7.4kW
• Type 2: AC, 3-phase plug, generally used in EU and Australia. It has 7 pins. Charges up to speed of 43kW.
• CCS-Type 1: 7 pins in total (5 pins, and 2 pins below in a separate enclosure).
• CCS-Type 2: 9 pins in total (7 pins, and 2 pins below in a separate enclosure)

How do I know which plug to use?

Don’t worry! Unless your EV is one of the first ones such as a Nissan Leaf (with a CHAdeMO fitting) it will come with a charging cable of the correct type according to where you live. In American and Asian markets this tends to be a Type 1 plug. The UK, EU and Australia use Type 2, with 7 pins.

For fast charging at public charging stations, you will use a CCS fitting, which adds 2 additional contacts below either a Type 1 or Type 2 plug. Only with the extra 2 pins of the CCS will you be able to use high-power DC fast charging.

You may find you need to buy additional EVSE equipment to have the ability to adapt from and to any fitting.

‘Level’ refers to the speed of charging.

Levels

Now we can discuss charger LEVELS. Levels refer to charging SPEED (how fast you can charge your battery). Chargers have 3 levels of charging capability: levels, 1, 2 and 3.

• Level 1 = AC. Slowest charge speed. This is where you plug into a Standard Power Outlet. It’s also referred to as a trickle charge, or granny charger. In the US, it’s a slower device rated ‘Level 1/120V’. In Europe and Australia ‘Level 1/220 to 240V’. If your car is near zero% charge it can take over a full day (and up to 40+ hours) to charge to 100%.
• Level 2 = AC. A Level 2 charger is called a Fast Charger. 7 – 11kW. It has its own wired-in circuitry & device on the wall such as a Wallbox, Tesla charger, or JuiceBox, Blink HQ, ChargePoint, Electrify, Grizzl-E. Autel and more. These all charge up to 7kW for single-phase or up to 22kW for three-phase. In residential applications, Level 2 equipment charges through 240V (208V commercially). It will take from 4 – 10 hours to charge your car. There are, however, car-initiated limitations: If your car’s onboard inverter is limited to 11kW as many currently are, your Level 2 Charge speed will be limited to 11kW. The only way to exceed it is to level up to a…
• Level 3 = DC. A Level 3 charger is called a Superfast charger. You’ll almost never encounter these installed in domestic homes. Superfast charging with commercial equipment 25kW upwards (but usually 50kW upwards and up to 350kW at present, though 500kW planned for commercial operations (which would likely be used for buses and trucks). You can charge your EV up to 80% from between 20 mins to 1 hour.

An extra few words about Granny Chargers

All Granny Chargers are Level 1 chargers.

Granny Chargers (Type 1) just plug into the wall (worldwide) to provide Level 1 charge rates. These can be easily obtained at home by using a wall charger or other plug-in device.

There is a Type 2 Granny Charger, but not if you’re in the US. Naturally, it’s for AC charging, but it’s only used in the EU, UK and Australia. The fitting is called a Mennekes plug, so if you’re in the US you don’t need to know any more about that, OK?

But just in case you need to know about it, the Mennekes plug has 7 pins and allows for single- and three-phase charging at 3.7kW-7.4kW AC. Its name comes from its German manufacturer Mennekes. Adopted as the EU standard for EVs in 2014, it is the most common EV connector in the UK.

If you want to charge at a higher level at home, you will need one of those Fast Chargers mentioned above that is specially wired-in.

So, now with levels much clearer, and you know more about the differences between the two types of charging, AC and DC, here’s a quick and dirty reference:

All equipment at home is AC

Any superfast-charging on a public network that charges at 50kW or higher will be DC

AC uses the onboard charger in your car (inverted to DC before the electrons flow to the battery)

DC fast-charging bypasses the car’s internal charger and delivers DC power to the battery directly at much higher speeds.

Charging Time

Your battery has a brain (of sorts). It’s referred to as the Battery Management System or BMS for short. It regulates battery function, preserves and prolongs battery life, and maintains safety. There’s a BMS in almost every rechargeable battery-operated device, like a phone or laptop. See definition in the glossary.

Most EVs also have a thermal management system to manage the effects of ambient temperatures, and the operational temperatures of driving and charging. It keeps the battery at optimum temperature (and can heat and cool appropriately).

Your battery will become hotter with charging, or if it’s a very hot day. Resultant charge speeds will be slower. Freezing weather cools the battery and also slows down charge speeds.

Charge speed is regulated by your BMS, which controls the thermal management system for a safe charge at an optimal speed (which varies).

Charging times at home, community chargers in shopping centers and places of work

For AC charging, charge time depends on:

• the capacity of your onboard charger (that comes in your EV),
• the power level of the charging equipment (the current you feed in from your house),
• the ambient temperature, and of course,
• the size of your battery will make a difference (a bigger battery takes longer to charge).

The time taken to charge depends on a number of factors:

Your equipment at home AND the quality (level) of public charging network and equipment:

The equipment you use at home: what most people call a charger, is actually an EVSE (EV service equipment) and usually refers to devices like a specialized box on the wall, or the cable that comes with your car that plugs into an ordinary outlet. The EVSE is just the means of getting the electricity to your car at the right power level, and safely.

Your car’s onboard charger: What most people don’t realise is that the charger is IN your car. It is only used when you use Level 1 and 2 chargers to charge your car with AC electricity supply. The internal charger in the car converts that power with an onboard inverter, to DC charge. You charge your car with AC, at home, work, supermarket. Anything up to 7kW single phase, and 22kW three-phase, is usually AC. The thing that’s on the wall in your garage is not actually a charger. It’s a device, part of your EVSE.

A public charger that is DC bypasses the car’s onboard charger and sends DC power straight to the battery. This is why it can charge at speeds above 22kW. Most cars only go to 11kW with their onboard charger. That may change to a standard 22kW in the future. The only time you rely on a charger outside of your car, is DC fast-charging.

The maximum ampage or current in your home or office environment. Homes are mostly supplied with single phase power, and most business premises will have 3-phase power. If you’re charging from a single-phase supply, you will have a fraction of the capacity to charge and it will take longer to charge, than with a 3-phase supply.

Granny charger (Type 1) just plugs into the wall. These can be easily obtained at home by using a wall charger or other plug-in device. (The Type 2 Granny charger is naturally for AC charging, only used in the EU, UK and Australia and is called a Mennekes plug. It has 7 pins and allows for single- and three-phase charging at 3.7kW-7.4kW AC.).

Do I need to fast-charge if I only drive about 40 miles per day?

You might only commute 40 miles (or 65km) daily. You could easily get by with a Level 1 charger (where you plug into the wall). Level 1 charging time: You would get a full recharge overnight.

Upgrade to a Level 2 charger and for that same 40-mile daily travel, a total replenishment of your battery would take less than 2 hours. For this you would buy a Level 2 Home Charger. It needs to be installed by a licensed electrician as it uses a 208 – 240 Volt outlet to support the higher-powered equipment. Many public chargers—such as those installed at work, shopping malls and other public centers where you might happen to park for significant time—use these Level 2 chargers.

For DC, charging is superfast charging, and not usually possible at home

DC charging—superfast charging—bypasses your car’s onboard charger and directly charges your battery. You have to have the right CCS-Type 1 or CCS-Type 2 plugs. This direct connection means much faster and far more powerful charge. With top charging speeds (as long as all your charging and EVSE ducks line up in a row) you might gain as much as 10 – 20 mile’s range per minute (16 – 32km per min).

All cars have a 12-Volt battery

Just as in all ICE cars, EVs also carry a 12V lead-acid battery onboard. This is distinct from the big battery that powers the car itself, just as a petrol car has a separate engine.

Electric car battery size matters

The size of an EV battery matters. Measured in kilowatt hours (kWh), it determines how powerful the battery is (how much energy it can store and have access to). The smallest car batteries in EVs are as low as 17kWh and as high as 150kWh. A typical 30 kWh battery pack will be physically smaller than a larger and denser 100kWh battery pack.

Voltage of electric car batteries

The lithium-ion battery that powers the movement of the vehicle is typically run on a 400-800V system.

400V or 800V. Which is better?

Well, it’s like this: The higher the voltage (architecture), the quicker the charging speed and the lower the time to charge.

Until recently, a maximum 400V architecture has been standard for electric vehicles. Tesla vehicles range from 350 – 400V.

The Korean based Hyundai Motor Group that produces Hyundai, Kia and Genesis vehicles, and also Porsche and Audi, have already committed to 800V architecture and there are a number of 800V cars already on the market.

At present, the biggest downside to 800V architecture EVs is the cost to engineer. However, it is very likely that by 2025, 800V will be the standard for all EVs. The Hyundai Motor Group has already proven it can already be competitive on price.

But comparing 400V and 800V shows the 800V has very clear advantages:

• 800V cars halve the charging time.
• Higher voltage means lower current.
• Lower current means reduced heat.
• Lower heat produced means less power directed to battery cooling systems.
• Lower current means charging cables are thinner, less bulky.
• Thinner cabling means other electrical components can also reduce in size.
• The car is lighter in weight and more efficient.

Charge speed of 800V

The car’s 800V architecture coupled with ever-faster-charging batteries (a technology is changing rapidly), will foreseeably deliver a 10 – 80% charge within 10 minutes to better the currently slower rates of charge.

When the voltage is doubled, you have the potential to deliver twice the energy into the car. This means the reason given for the need for the ever-increasing EV range is one that is losing importance, as EV charge times reduce (due to improved battery technology coupled with 800V architecture.

400V and 800V cars and superfast chargers

So, if you happen to pull up to a superfast charger that is rated for an output of 350kW, will your car charge superfast?

Maybe, maybe not. If your car is 400V the extra charging capability will not improve your charge speed.

A car with an 800V system is better equipped to handle the higher current.

Here's a breakdown of typical battery voltage architecture:

350V battery is in the Tesla Model 3 and Model X

375V Tesla Model S

400V Tesla Model Y

There is a good selection of EVs that have 800V architecture:

• Audi e-Tron GT
• Genesis G80 EV
• Hyundai Ioniq 5
• Kia EV6 and
• Porsche Taycan

The only EV with more than 800V is the Lucid Air EV, which has a whopping 900V architecture to make it capable of charging faster than any other EV.

Brands that have committed to 800V:

• BYD
• General Motors
• Lotus
• Polestar
• Volvo

Hybrids only have batteries between 100 and 300V.

A quick working example:

A Tesla Model S has a 100kWh battery. But as you now understand, a Kia EV6 with a 77.8kWh battery will charge faster, not just because of the battery size, but because its 800V architecture allows it to charge at more than double the speed of the Tesla.

Here's a question most people ask… Does my car charge faster when the charger is bigger? (myth exploded)

The bigger the charger, the faster my car charges, right? Well, NO. That’s not right.

The bigger the charger, the faster my car charges, right? Well, NO. That’s not right.

The answer is NO! There’s more to it than that.

While fast- and super-fast chargers (DC chargers) have power levels from 50 – 350 kW, it doesn’t mean the higher the charger’s speed, the faster you charge. But why not?

The speed at which your car will charge (measured in kW) depends on the battery type and its capacity (its size is measured in kWh). Batteries vary widely among car makes and models. While many EVs boast superfast charging, this can ONLY potentially occur at a public Level 3 fast charger. Such highspeed charging is impossible with a domestic supply (home) where it can take several hours to reach a full charge.

Here’s a scenario that will help pull all this info together.

• Your car’s 70kWh battery is almost empty. You pull up to a 350kW ultrafast charger.
• By the laws of physics, it should take only 12 minutes to fully charge. One fifth of an hour. (70/350 = 1/5^th of an hour = 12 mins).

However, unfortunately, it’s more complex than that.

There are 2 key things:

• Your car has a maximum charging speed. And...
• Charging is not linear. The rate of charge takes a little time to speed up, and it slows down significantly after 80% charge has been reached.

You may have heard the word ‘architecture’ in relation to your car’s battery. The speed your car can charge is dependent on this ‘architecture’. It is a combination of the maximum voltage, and the max ampage it can accept. It is often expressed as such:

Currently, almost no cars actually charge at the maximum 350kW speed. EVs will have a range of charging speeds depending on the model somewhere between 50kW and 250kW

Another look at this example. Same charger, same 70kWh battery. But your vehicle can only charge at max 70kW (DC charger). The fastest it will charge, without adjusting for the variable charging speed curve, will be 60mins from 0 – 100% (in theory). This will be the case for any charger 70kW or ABOVE (regardless) because the restriction lies with the CAR.

To know what your maximum charge rate is, consult your vehicle’s manual or ask your dealer.

For most vehicles and travel conditions, 150kW will be ample.

It’s likely that this technology will rapidly evolve as batteries become better designed, have larger capacities, and charge faster.

You may find in some locations, the load across multiple chargers is spread if all chargers are running. This may be to try to balance local loads on the grid. So don’t be surprised if that 350kW charger is only running at 80kW to your car right now.