If gas-pump etiquette isn’t officially A Thing, it should be. I mean really, some people. After filling up, they enter the kiosk to pay – then a buy pack of smokes, ponder which lottery ticket to pick and withdraw some cash from the ATM. Oh, and while they’re at it, they use the washroom, too.
All this while their vehicle is blocking access to the pump for other drivers who just want to gas up and go.
Yet that’s nothing compared with the potential for selfishness at a public electric-vehicle (EV) charging station. Depending on the vehicle and the charger, the time to fully recharge is more likely measured in hours than minutes.
“Take only what you need and limit your charge to 30-40 minutes,” is the No. 1 rule of charging etiquette, according to B.C. Hydro. “Try not to treat the fast-charger network as your go-to way to charge, as the time you spend parked at a station can prevent others – including those in serious need of a charge to get to Point B – from using a station.”
But it’s also in your own interest to use fast chargers only when you must. EV batteries don’t like to be charged fast, and they don’t like to be charged fully, says Sankar Das Gupta, chief executive officer of Mississauga-based battery manufacturer Electrovaya Inc. “Generally, lithium-ion batteries lose capacity when kept fully charged or at the top of their cycle. Many car makers will suggest not to fully charge the battery unless you are planning a long trip.”
Most EVs’ battery management systems (BMS) are programmed keep true state of charge (SoC) below 100 per cent, even if the vehicle’s gauge tells you it’s “full.” If you choose to keep it even lower, some EVs can be programmed to terminate charging at a predetermined SoC.
Conversely, Das Gupta says, some EVs have a “range extender” setting that lets the vehicle achieve a true 100-per-cent charge if you are planning a long trip. “Doing that a few times a year doesn’t really matter for longevity.”
Still, that 40-minute limit isn’t as restrictive as it seems. You may have noticed that the specs for most EVs quote fast-charge times up to an 80-per-cent charge, not 100; at higher SoCs, the rate of charge falls steeply, and it’s not worth the time it takes to squeeze in that last 20 per cent. It’s also not worth the stink-eye from other EV drivers waiting their turn.
According to the website EV Database, the average time to fast-charge from 10 per cent to 80 per cent for EVs sold in Canada is indeed about 40 minutes.
Another reason to avoid DC fast charging is the cost. Whether priced by the minute, by the kilowatt-hour delivered or at a flat rate, high pricing tends to negate the “fuel” cost saving of electricity over gasoline compared with charging at home. You also pay if you stay plugged in after charging has ended.
If we are agreed that EV ownership makes most sense if you can recharge at home – preferably at low, off-peak rates – what else should you know?
Level 1 chargers
Every EV comes with a portable, on-board 120 V charger. Plug one end into the car’s charge port and the other end into any standard 120 V outlet. It’s slow – about 8 kilometres of range recouped per hour. That may be enough for a plug-in hybrid or an EV driven less than 60 kilometres daily, but limiting otherwise. One plus: If caught short away from home, you can top up from any 120 V outlet (with the owner’s permission, of course). Level 1 chargers usually draw 10 to 16 amps (some are adjustable), so make sure your system can handle it.
Level 2 chargers
Some EVs (for instance, newer Nissan Leafs) come with a 240 V portable charger that can be plugged into any handy dryer outlet. The free charging stations often found outside restaurants, malls and so on are also Level 2. And Level 2 is also what most EV owners would install at home. Connecting cables are usually fixed to the charger and at least 20 feet long.
Plug’n Drive, a non-profit that promotes EVs and is backed by utility companies and the automotive industry, lists 16 models ranging from $800 to $1,200. They can be hard-wired, or there are plug-in models that are easy to take with you if you move. Unless you already have a handy 240 V stove or dryer outlet to plug into, you’ll need a qualified electrician to install the unit. Most chargers output 30 amps – appropriate breakers will be needed.
Level 2 is the most you can use on most plug-in hybrids, but a typical charge rate of 30 kilometres per hour is ample for that. Tesla offers its own version of a home charger that, depending on the model and the power your home can safely provide, can deliver up to 77 per hour.
Level 3 chargers
Level 3 DC Fast Chargers are the EV equivalent of gas stations. These increasingly ubiquitous public chargers typically deliver 400 volts and up, but their outputs are expressed in kilowatts. The baseline in Canada is typically 50 kilowatts, but 100-, 150- or even 350-kilowatt charging is out there, too.
That said, charge rate is limited by what your EV can handle – from below 50 kilowatts to over 150 kilowatts among EVs sold in Canada. You can still use higher-output stations – the vehicle itself will determine how much it can actually take – but what’s the point?
DC Fast Charging is fast and efficient, but it puts more strain on the battery and may reduce its lifespan.
Tesla’s proprietary network of Superchargers offers 150-kilowatt – and more recently 250-kilowatt – DC fast charging. At 250 kilwatts, some more recent Teslas can do the 10-to-80-per-cent benchmark recharge in just 19 minutes. Historically, Tesla has used its own unique connectors, but adapters are becoming available so Tesla vehicles can use non-Tesla chargers, or vice versa.
When all is said and done, we know that overcharging a battery is a bad thing. But so is range anxiety. What to do?
“With batteries, in general, it is always advisable to charge when you can,” says Brian Millar of Plug’n Drive. “If you fully top up a battery, fully drain and then fully top up again, that is called deep cycling and is notoriously bad for batteries. So the best advice would be for the driver to set their car or charging station to not go above 80 per cent but to plug in whenever they have the opportunity.”