The Joy of Fueling at Home
Filling a gas tank is faster than charging a battery, but this simple comparison misses an important point: Charging an electric vehicle at home is extremely convenient. You can’t install a gas pump inside your garage. An EV can leave the driveway every morning with a fully loaded battery, and charging at public charging stations only becomes necessary when travelling longer distances. About eighty percent of charging is done at home, and most EVS tank up while their owners are sleeping.
All EVS have a built in device called an “onboard charger” that regulates the flow of electricity into the battery. The speed that an EV can accept electricity is called the “acceptance rate”. Decent onboard chargers have acceptance rates above 7 kilowatts. Tesla’s vehicles have excellent acceptance rates in the high teens. Most onboard chargers can accept electrons as fast as a home charger can dish them out. Rapid acceptance is more important when charging at high voltage public superchargers.
Level One home charging stations run on 120 volts. Level Twos need 240. All EVS come with a Level One charging cable that plugs into the EV at one end and a common 15 amp wall outlet at the other end. This is called “trickle charging”. It’s relatively slow, but some folks don’t mind trickling. The average car spends 95% of its time just sitting around, and an EV can be refueled at home whenever it’s not being driven. For people who don’t drive all that much, charging slowly at Level One can be perfectly adequate.
Most EV owners need the additional speed of a Level Two home charger. Some are faster than others, but most can fill the EV’S battery before the sun comes up. The higher the charger’s amperage, the faster it delivers a charge. Standard chargers draw 12, 16, 24, 32, 40, or 48 amps. These correspond to six standard 240 volt circuit breakers that are rated for 15, 20, 30, 40, 50, or 60 amp circuits. The amperage of the charger can’t exceed 80% of the amperage of its circuit breaker. Some people have a charger hard-wired straight to a new circuit breaker. Others add a beefy new receptacle as well and purchase a charger with the proper plug. Lucky people with an unused 30 amp dryer receptacle simply purchase a 24 amp charger and plug it in. Some chargers draw more amps than the electrical panel can handle. An experienced electrician can calculate the limit of the additional load. Clipper Creek builds excellent home chargers, and browsing their website is a great way to learn more about charging equipment.
Some folks who sincerely love the planet have no way to charge at home. For them, a hybrid is a better choice than an EV. Those who do have a garage quickly learn to appreciate the joy of refueling their EVS at home while they’re fast asleep, dreaming about a world without climate change.