How It Works: Electric vehicle charging

You can usually find a gas station wherever you want to go, but locating a public place to charge an electric vehicle can be an issue for these fuel-free machines. There's also the length of time it takes to charge, which primarily depends on the type of charger being used.

At the moment, there are three levels of charging available, each quicker than the next, but also increasingly more expensive.

Level 1 is 120 volt, which is the standard household plug. Yes, you can plug an electric car into the same type of socket that powers your coffee maker, using a cord that comes with the vehicle, but it takes a long time. Depending on the battery capacity, an all-electric car can require as much as a full day or more to go from depleted to fully charged. Plug-in hybrid vehicles (PHEVs), which provide a relatively short period of fuel-free driving on a stored charge before reverting to regular hybrid operation, can take as long as 12 hours.

Alexis Georgeson demonstrates how to charge a Tesla model S electric car during a ribbon-cutting for Tesla's first Ontario supercharger stations in Toronto , Ontario, Thursday,September 4, 2014.

The next step up, Level 2, uses 240 volts, the same as some larger appliances such as clothes dryers. It's the most common level used, either with a household charger that vehicle owners have installed at home, or at most public charging stations. Virtually all electric vehicles and PHEVs are able to charge at this level.

On Level 2, a PHEV generally takes about one to two hours to charge from empty, while a full electric vehicle usually requires between about three to six hours, again determined by the battery size.

Both Level 1 and Level 2 charging operate on AC power, and both use the same charging port on the vehicle. The third choice, Level 3, is direct current (DC), which requires a specific vehicle port. One of these chargers, which are used primarily on all-electric vehicles rather than PHEVs, can fill a depleted battery to approximately 85 per cent in about half an hour.

The "85-in-30" statistic is because of how batteries charge. Rather than a steady flow of electricity, they charge rapidly when they're empty, but the rate slows down as they start to fill up, usually around 50 per cent. It tapers off even more once it gets above 80 per cent full, taking it beyond the half-hour timeframe that makes this on-the-fly charging more appealing to drivers.

The problem is that Level 3 chargers are rare, and that's mostly because they're expensive. A public DC charging station can be as much as $100,000 to install. While some electric vehicles include both AC and DC ports, a DC port may be optional or unavailable on particular models. Level 3 charging is also harder on the battery, although most manufacturers say it shouldn't be an issue over the vehicle's expected lifetime.

2018 Nissan Leaf

As more automakers get into electric vehicles, and more companies into charging stations, a growing concern is lack of standardization. You can fill your gasoline vehicle from any gas pump nozzle, but the plugs on public charging station cords don't always fit every vehicle. At the fast-charging stage, Level 3 stations can have different systems that aren't always compatible with all vehicles. These include the most common one, CHAdeMO (an acronym for its Japanese name), developed by Tokyo's power utility in conjunction with some car companies, and CCS (Combo Charging System), generally preferred by American and German automakers. China has its own specific system. There's also a high-performance fast-charger that's unique to Tesla, and can't be used with other electric vehicles.

Apart from the cost of installation, the demand for each type can limit fast-charge infrastructure. A public station may be more likely to offer CHAdeMO simply because there are more compatible electric vehicles on the road, including the Nissan Leaf.

At the moment, no one's quite sure what system will ultimately turn out to be the "universal gas nozzle" that can recharge every electric vehicle. Auto and charging station manufacturers would love to see standardization for all plugs and chargers, but right now no one's even sure what association or governing body is going to take the initiative for setting and maintaining standards, whether from country to country, or at the individual vehicle level.

Another question is who will pay to create an extensive and viable charging network. Up until now, neither automakers nor municipalities have had to worry about refuelling, which was handled by oil companies through franchised stations. The current EV infrastructure, such as it is, includes stations installed by car manufacturers, local governments, and independent third-party companies. While provincial, state, and federal governments have all promised comprehensive networks of stations to give electric vehicles the potential for coast-to-coast driving, they have yet to materialize.

Studies show that the vast majority of electric vehicle owners charge their cars at home, usually overnight, even when they can charge at work or at a public station. Even when public facilities are available, the time required can be a stumbling block for many people. It isn't just the cars themselves, but how and where to effectively charge them, that will ultimately determine how successful electric vehicles will be.

Source: How It Works: Electric vehicle charging