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Charging Basics

Charging an electric vehicle (EV) is incredibly easy, especially these days, as you can conveniently charge at home or at the expanding network of charging stations located at workplaces, apartment buildings, hotels, restaurants, public garages, and towns and villages. Most EVs come with their own Level 1 charger, which can simply be plugged into a standard outlet at your home. Or for even faster home charging, you can install Level 2 charging. This means you can drive EVs even farther and more conveniently.

Charging Levels

Level 1 charging requires a standard 120-volt outlet. Most electric vehicles come equipped with a cord that you can simply plug into the wall. Charging times for these average around four miles of range for each hour of charging, making them ideal for commutes under 40 miles. It's as simple as charging a smartphone or laptop. Many factors influence electric vehicle (EV) charging speed, including the EV battery's state of charge, battery deterioration, use of power while charging, ambient temperature, and power level of EV charging equipment.

  • Faster charging: Customers who upgrade their home outlet to a 240V can increase their speed of charging from 4MPH to 25 MPH. To charge an EV from 0-80%, your charge time decreases from 30-50 hours to 4-10 hours!
  • More convenient: Upgrading to a Level 2 charger provides customers with a full charge overnight, eliminating range anxiety when navigating unexpected situations in your day.
  • Lower charging cost: Upgrading to a Level 2 charger reduces the time to charge, resulting in higher efficiency charging, saving customers roughly 10% on electricity consumption per charge cycle. Savings depend on EV model and temperatures.
  • Fewer greenhouse gas emissions: Customers who upgrade to a more efficient charger reduce electricity consumption, resulting in roughly 10% fewer CO2 emissions per charge cycle.  
  • Increased home value: Upgrading your home to support level 2 charging increases your market value by meeting the increasing demand of EV adoption, future proofing tenants needs, and meets the Board of Building Regulations and standards for newly constructed homes

Level 3, or direct-current fast charging (DCFC), is the fastest charging available for passenger vehicles. You cannot install a DCFC unit in your home, but they are widely available for public use for charging on the go. Fast chargers can deliver a charge of up to 200 miles (depending on vehicle make and model) in just one to two hours.

Customers can increase their speed of charging from 4 MPH to 25 MPH by upgrading their home outlet from 120V to a 240V outlet. National Grid has rebates for Massachusetts electric customers of up to $700 to support the cost of this upgrade. See program details


Range Basics

EV battery size is measured in kilowatt-hours (kWh). The more capacity a battery has, the farther your vehicle can travel on a single charge. Different EV models can travel a different number of miles for every kWh of battery capacity. The vehicle's battery size and efficiency together determine its range, along with driving conditions. For example, in the Northeast, the weather is always a factor when it comes to travel. That remains true for EVs, as cold weather will impact the range of your EV. That said, EVs can handle whatever a Northeastern winter can throw at them. For more information on range, the Environmental Protection Agency's miles-per-charge ratings for EVs are a good reference source until you become familiar with your vehicle.


Electric Vehicle Charging Station Locations

Frequently Asked Questions

The simple answer: it depends on many factors, including the charging device, size of the EV battery and the power source. Charging a vehicle using a common 120-volt (Level 1), 14-amp receptacle  provides on average 4 miles of range for each hour of charging. A 240-volt outlet (Level 2), on the other hand provides on average 25 miles of range for each hour of charging. The fast-charging stations (Level 3 or DCFC) available in public spaces can deliver on average up to 200 miles of range in just one to two hours.

There are many types of EV chargers for your home. Three key considerations are safety, charging management capabilities, and available rebates.

  • Safety: Whatever you use, make sure your charger is safe and is tested for safety from UL, CSA, Intertek, or some other recognized testing laboratory. You should avoid chargers that are not tested for safety, including some chargers available online.
  • Charging Functionality: Some charging equipment is simple in that it only provides electricity to the EV.  Some charging equipment is internet connected, providing you helpful features, including the ability to optimize your charging.  The latter charging equipment requires a cellular or Wi-Fi network for all functionality to be operational.  
  • National Grid now offers programs where you can save money on your electric bill if you enroll your compatible EV or internet-connected charger.