The cost of buying an electric vehicle is slowly coming down, making it easier for more drivers to go electric. EV drivers can enjoy tax credits and lower maintenance costs. But how much does it cost to charge an electric car? Here’s what the math says.
Charging Cost Formula
In a blog on this topic, Investopedia suggests using this formula: Charging Cost = (VR/RPK) x CPK. In this situation, VR refers to Vehicle Range, RPK refers to Range Per Kilowatt-hour (kWh), and CPK refers to Cost Per Kilowatt-hour (kWh). Too confusing? Automotive journalist John Voelcker told Kelley Blue Book, “A conservative rule of thumb is that an electric car gets 3 to 4 miles per kWh… So divide the total miles you drive each month by 3 to get the kWh you would use monthly. Multiply that number by your cost per kWh. The dollar amount you get will most likely be lower than what you pay each month to buy gasoline.”
“How much does it cost to charge at ___?”
Once you know the total kilowatts needed for your vehicle, you can start thinking about your own vehicle usage. Charging costs can vary depending on your driving patterns, season, type of chargers, and where you typically charge. The US Energy Information Administration tracks the average prices of electricity by sector and state, as seen in the table below.
Charging your EV at home
If you own or rent a single-family home with a home charger, it’s easy to calculate your energy costs. Simply check your monthly utility bill for your actual usage and rates. In March 2023, the average price of residential electricity in the United States was 15.85¢ per kWh before increasing to 16.11¢ in April. Idaho and North Dakota customers paid as little as 10.24¢/kWh and Hawaii customers paid as much as 43.18¢/kWh.
Charging your EV at a commercial charger
The cost to charge at a commercial EV charger can vary. While some locations offer free charging, others use an hourly or kWh fee. Faster 19.2kW Level 2 chargers like the Series 8 can deliver up to 65 miles of range per charging hour, but beware: your maximum charging speed is limited by your onboard charger. If your vehicle is capped at 7.2kW, your Level 2 charging will be capped at that level.
Duration-based fees: At locations that use an hourly rate, you can expect to pay for the amount of time that your vehicle is plugged in.
kWh fees: At locations that use an energy rate, you can use the charging cost formula to estimate the cost to charge your vehicle.
However, when using a commercial charger, there might be a markup on the electricity cost, so you need to know the price the station host set by the host. Some hosts choose pricing based on the time used, others may charge a flat fee for using the charger for a set session, and others will set their price per kilowatt-hour. In states that do not allow kWh fees, you can expect to pay a duration-based fee. While some commercial Level 2 charging stations are offered as a free amenity, Investopedia notes that “the cost for level 2 ranges from $1 to $5 an hour” with an energy fee range of $0.20/kWh to $0.25/kWh. Charging is different when using a Direct Current Fast Charger (DCFC), which is one reason why many states are now allowing kWh fees. While DC fast charging is much quicker than Level 2, it is often more expensive. As noted in one National Renewable Energy Laboratory (NREL) paper, “charging price for DCFC in the United States varies between less than $0.10/kWh to more than $1/kW, with an average of $0.35/kWh. This variation is due to different capital and O&M cost for different DCFC stations as well as different cost of electricity.” In addition, it’s important to note that you cannot use a DCFC to charge a plug-in hybrid electric vehicle. You can expect to take a few hours to charge your battery at a Level 2 charger, while a DCFC will be able to charge it in under an hour.
Variations in the Cost to Charge
But we’re not done yet. As with gasoline, electricity costs can vary by region or day. If you are planning a road trip, you can expect to see different pricing policies based on region. Here are a few ways that pricing plans can vary.
Pricing in different regions
As previously mentioned, the price for electricity around the United States fluctuates broadly between regions. In a state like North Dakota, electricity can be under 10 cents/kWh while in Connecticut, it may cost over 33 cents/kWh.
Pricing at different times of day
Many electricity providers have special rates for “off-peak hours.” These are generally in the evenings, on the weekends and holidays, and overnight. Some site hosts may decrease their pricing during these times. If you’re charging at home or using a commercial charger in the evening, you may be able to shave off a few dollars from your total charging cost. If available, Time of Day pricing should be noted in the charging station app that you’re using to charge.
Battery levels
Thus far, we have been talking about how much it is to charge an EV from empty to full, but this isn’t usually the case with EVs. As with ICE vehicles, most EV drivers do not allow their vehicle’s battery to get completely depleted, and neither do most drivers regularly charge their batteries to 100%. It is recommended to always have 20-80% of charge to preserve your lithium battery’s health. Electric vehicles offer a feature called regenerative braking, which allows the vehicle to recapture kinetic energy while driving. However, you can only store this electricity in the battery if it has room to store energy. For that reason, many EVs cap charging at 80%. EV batteries charge the first 80% relatively quickly, but the final 20% is charged more slowly when using a DCFC. The final 20% will take about as long to charge as the initial 80%. Similar to how some cell phones now slow down charging to preserve the lithium battery, the computer in many EVs will also slow down (or stop) charging once your vehicle reaches a preset threshold. While you cannot overcharge an EV, and energy flow will end once your battery is full, it is important to remember that in most cases, you do not need a 100% full battery.
EV costs compared
To help you compare the cost of owning a given vehicle, United States Department of Energy’s Alternative Fuels Data Center has a Vehicle Cost Calculator that you can use to see how much it would cost to own a specific electric vehicle. Blink also offers a search tool for finding residential EV charging installation tax incentives and other funding options for installing a Level 2 charger at your home. Thinking about getting a Level 2 residential EV charger? Blink has you covered with our HQ150 and HQ200 home EV chargers. You can also contact our sales team about installing commercial Level 2 EV charging stations at your multifamily community.