EV Charging guide

As you are undoubtedly aware, electric vehicles will dominate global roads in a few years. Climate change and the need for sustainable energy have seen governments press fast-forward to the introduction of EVs. Electric charging stations will now be omnipresent in place of gas stations, supermarkets, car parks, and elsewhere. If you don’t relish the idea of sitting in your vehicle and waiting several minutes for it to charge, home charging is also an option. A deluge of home chargers is on the market now, and choosing which one to buy can be confusing. If you need a little clarification, read on.

What To Be Aware of Before Searching for an EV Home Charger

There are presently two residential chargers to choose from — Level 1 & Level 2 chargers.

Level 1

• Deliver a charge at 110 or 120 volts.
• They require no extra wiring to your home — plug and charge.
• These are the slowest chargers and can take a day or more to charge your car.

Level 2 

• Delivers a charge at 220 to 240 volts.
• Requires a professional electrician to help with the residential installation.
• Varies in price from £200 to £1000 (not including installation)
• Can charge a BEV (Battery powered Electric Vehicle) from empty in 4-10 hours
• Many are compatible with Amazon Alexa and Google Assistant
• It can be pre-programmed and also plug-in or hardwired.

Direct Current Fast Charging (DCFC)

• Not generally used in residential settings and instead used along highly trafficked commercial roads (in place of gas stations)
• Offers the fastest charging speed of a (B)EV from zero to 80% in 20 minutes to 1 hr.
• Not used with hybrids, only BEVs.

What Determines Your Charger Choice?

In residential applications, the type of home you have and its power supply will affect your charger choice. The most common type of household wiring is a 1-phase connection that supports Level 1 chargers (using a 120-volt SC plug). 

All EVs come with a Level 1 charging kit. However, the 8-12 hour charging time is a big turn-off for many EV owners. In this case, you’ll need an upgrade to a 3 Phase/Level 2 charger using a 240-volt AC plug and need to have your home professionally rewired accordingly. 

A three-phase charger works on 400 volts and 16 amps of current and can charge at a rate of 11 kWh, three times the speed of a 1 phase charger — which equates to under 6 hours typically. However, each car has a different charging capacity and knowing which capacity your car charges at is essential for selecting a charger.

Indoor and Outdoor Chargers

Yes, indoor and outdoor chargers are different, although the difference is mainly restricted to their weatherproofing properties. Outdoor weatherproof chargers can be affected by cold climates slowing down charging speeds. Also, exterior Level 2 chargers come with varying cable lengths. So make sure you choose one that’s long enough.

An On Board Controller: Why it Matters

An EVs onboard controller (OBC) is an interface that manages the communication between your EV and its corresponding charging station. As EV batteries need DC to charge, AC chargers must use a converter between the socket and the battery. Don’t fret too much about it, as this is where an OBC comes in. It’s usually included in AC charging vehicles and will be explained when purchasing/leasing the car. In residential settings, however, it’s still good to check that your OBC can manage the flow of electricity from the grid to your EV’s battery. Your OBC must be compatible with the grid locations where it will be used and also with the charger you intend to use.

Pros & Cons of a Tethered and Untethered (Socket) Home Charger

Tethered Charger

A tethered charger is a one-stop shop. It contains everything in one location — the charger and the cables attached to your car to charge. It’s the same concept as driving up to a pump at a gas station and then driving off. Level 2 chargers are nearly always tethered. If the EV charging technology of a car changes, then the charger will need to change, too, as the plug will no longer be compatible. However, for the foreseeable future, this won’t be an issue. Also, like petrol pumps, charging lines need to be returned safely to avoid driving over them!

Untethered (Socket) Charger

This is just a wall socket you plug your car into as you would an appliance. In this case, the car owner provides the charging cables (which usually come with your vehicle.) The main inconvenience is taking the cables in and out of your car for each use. The upside of a tethered charger is that you are future-proof. Should the cable requirements change, you can always upgrade. Another positive is neatness. — no hanging cables in your garage.

The Pros of Smart Chargers

Cloud-based smart chargers, like other apps, allow control from a smartphone. In this case, EVs and a charging device share a data connection. The main advantage of smart charging is the control and consumption of energy. For instance, it can limit energy usage during peak hours when it is most expensive and when most people use the grid. Smart charging allows utility companies to restrict energy consumption according to local grid capacities and specific energy tariffs. This feature is not available with traditional chargers.

Solar Power and Home Charging

Most homes are powered by the electric grid and billed to homeowners through their local utility/energy company. Solar panels allow a home to use its energy rather than the grid’s, thus saving the homeowner money through lower energy bills.

Net Energy Metering

When solar panels cannot produce enough energy for the home’s use, power is taken from the grid as usual. Equally, when the panels make excess energy (in hotter countries), energy is sent back to the grid. The homeowner gets credit for this the next time they need to use the grid’s power. 

How EVs Charge With Solar Panels

Five solar panels are needed to charge an average size EV. This is based on EVs running for 6km from 1kw of energy in their battery pack. So to drive around 50km per day, an electric car will need approximately 8kw of electricity to recharge what they use. The amount of energy differs from car to car. The more energy a car consumes, the more is needed. For example, you’ll need around seven 350-watt panels to charge a Nissan Leaf and 10 panels to drive 40 miles in a Porsche Taycan 45. It’s estimated that EVs are about 70% cheaper to run than petrol cars.

How To Directly Connect Solar Panels To Your EV Charger

To charge your EV using just rooftop solar panels, you will need the following setup:

• Rooftop solar panels
• A central string inverter. This combines the DC output of the solar panels with AC or micro-inverters that convert each panel’s output to AC.
•  A Level 2 EV charger. 

Conclusion

The move away from fossil fuels to charge our cars is not only good for the environment but also for our wallets. However, the move from ICE vehicles to EVs will present teething problems, especially for segments of the population who live in apartment buildings or park their cars on public streets. For those, public charging will be essential. For homeowners, rewiring to accommodate Level 2 chargers will require research and planning. However, by the time every home has an EV, expect the charging technology to have progressed. Although we’re still a long way off from charging an EV in the time it takes to fill a car up at the gas station, expect to get there eventually.