California Air Resources Board

Learn the Basics of Battery Electric Vehicles, Including How Charging Works, the Benefits, and the Limitations

How does charging work for battery electric vehicles (BEVs)?

• Much like conventional vehicles, BEVs need to be regularly refueled but instead of refueling with a gas pump, BEVs need to be plugged into an electric energy source or charging equipment. The amount of time needed to charge depends mostly on the power output of the outlet or charging station and the vehicle’s ability to receive a charge. The higher the station’s output or voltage rating, the faster the charging.
• Electric vehicle chargers are classified into three categories with varying voltage ratings: Level 1 Charging uses 110/120 volts, a Level 2 uses 208/240 volts, and a DC fast charger uses between 200 and 600 volts. Numerous manufacturers produce chargers with a variety of products and varying prices, applications, and functionality. Battery electric vehicles also have varying battery capacity, which will also play a part in how long charging will take. In general, the higher the battery capacity (measured in kWh) that a vehicle's battery contains, the faster charging will be, and the further the vehicle’s range will be, although many limiting factors need to be considered. For example, temperature can play a part in the speed at which batteries charge. There are also ways to maximize the usage of a BEV by using smart charging techniques to minimize the charging downtime. For example, a BEV doesn’t charge at a constant rate, it fluctuates during the charge and generally charges faster up to a certain percentage. Charging rates are faster at the beginning of the charge compared to when the battery gets closer to 100 percent capacity. Therefore, many BEV operators may choose to stop charging at 80 percent or 90 percent instead of a full 100 percent charge to spend their time more efficiently.
• Commercial BEVs can be charged at a privately owned power source, which could be a garage at a residence, or at a facility’s parking lot (depot charging). They can also be charged at a public power source or charging station. This strategy usually involves charging a BEV in the middle of a vehicle’s route using a DC fast charger, usually ending the charging process before the battery is completely full. There are also products available today to offer mobile charging options to fleets, with more manufacturers exploring these options all the time. Every BEV owner will need to consider their charging strategy based on their available resources and they should work with their local energy utility early in the planning process to determine what will work best.
• BEVs currently use an array of charging connector types. The SAE J1772 or J connector, is common for Level 1 and 2 chargers. The Combined Charging System or CCS Type 1 connector, combines the J connector with DC fast charging prongs on the bottom and is much faster. Finally, the SAE 3068 connector was developed with commercial charging in mind and while it is less common today, we can expect to see the technology become more common for the medium and heavy-duty vehicle market.

Learn more about battery electric vehicle charging using the following resources:

National Medium/Heavy Duty Zero Emission Infrastructure Map
Cal eVIP Electric Vehicle Charging 101
NRDC Electric Vehicle Charging 101
Drive Clean Electric Car Charging Overview
U.S Department of Energy Alternative Fuels Data Center: Electricity

What are the benefits of battery electric vehicles?

• While upfront vehicle costs for BEVs are currently higher than conventional vehicles, the total cost of ownership is typically lower. Electricity costs for fuel are generally lower than conventional fuels, although the fuel economy of medium- and heavy-duty BEVs is dependent on the load carried and the duty cycle. In the right applications these vehicles maintain a strong fuel cost advantage over their conventional counterparts. Also, upfront prices are likely to decrease to match conventional vehicles as production volumes increase and battery technologies continue to improve.
• BEVs report higher fuel efficiency because electricity is fundamentally more efficient than conventional fuels. Additionally, frequent starting and stopping and elevation decline allows BEVs to utilize regenerative braking systems to recapture energy, which extends the vehicle’s range.
• Electric motors have far fewer moving parts and do not require regular oil changes, spark plugs or fuel filters. Regenerative braking also extends the lifespan of brake pads by using the electric motor to decelerate the vehicle. These advantages lead to lower overall maintenance costs and increased savings.
• Using more energy efficient vehicles is an important part of the United States’ energy security and minimizes the need for imported oil. Also, the multiple fuel sources used in the generation of electricity results in a more secure and domestically generated energy source for the electrified portion of the transportation sector.
• BEVs produce zero tailpipe emissions, although the production of electricity may generate emissions affecting air quality.
• Drivers experience a more responsive motor, quieter ride, and less vibration. These vehicles typically also have great handling capabilities. The battery pack lowers the vehicle’s center of gravity, providing superior weight distribution and stability, and improved cornering that minimizes rollover risk.

Learn more about battery electric vehicle benefits using the following resources:

U.S. Department of Energy: Electric Vehicle Benefits and Considerations

What are the limitations of battery electric vehicles?

• Many heavy-duty vehicle owners say that limited range is their number one barrier to BEV adoption. While this may be an issue with early models, there are commercially available battery electric heavy-duty trucks capable of driving over 200 miles on a single charge. This range is ideal for urban deliveries, drayage, and other operations that do not require longer ranges. Additionally, new options for battery electric heavy-duty trucks capable of traveling longer ranges are being developed and are expected to reach the market soon.
• Upfront costs are currently higher for battery electric vehicles (BEVs) than for conventional vehicles, although a combination of declining costs, incentives, and innovative financing models can lower these upfront investments and reduce the impact. CARB is currently prioritizing financial incentive projects that will help ease adoption of zero-emission vehicles. For example, the Hybrid & Zero-Emission Truck & Bus Voucher Incentive Program (HVIP) offers point-of-sale discounts for zero-emission trucks and buses by working directly with dealers to apply the incentive at time of purchase.
• Battery prices remain a significant reason for the higher upfront cost of the battery electric vehicle. However, as the sales and production of commercial zero-emission vehicles increase, manufacturers will be able to provide battery producers with higher levels of demand and certainty, so battery pack prices are expected to decline across all types of vehicles.
• Battery electric trucks rely on electric charging infrastructure, which requires a shift for many owners in terms of measuring the range their vehicle can operate per charge and ensuring availability of charging locations. Vehicle owners may need to consider different charging strategies and this will often require planning ahead of time. Installation of electric charging infrastructure may have site limitations, result in additional construction costs, and require substantial planning. Many fleet owners will need to utilize publicly available charging infrastructure which is yet to be widely available. To address this, California has invested heavily in electrical utility infrastructure. The California Public Utilities Commission (CPUC) and the state’s investor-owned electric utilities (IOUs) are working towards accelerating widespread transportation electrification by ensuring that electric rates make electric vehicle charging cheaper than fueling with gasoline or diesel. The California Energy Commission (CEC) offers Energy Infrastructure Incentives for Zero-Emission Commercial Vehicles (EnergIIZE Commercial Vehicles), which provide incentives for electric charging and hydrogen fueling infrastructure to support fleets. Also, the Low Carbon Fuel Standard (LCFS) program creates incentives and a potential funding stream for electric charging infrastructure via a market-based system of tradable credits for clean fuel production.

Learn more about options to assist transition by using the following resources:

ZEV TruckStop  - Incentives & Funding
CALSTART’s Advanced Technology Truck Index: A U.S. ZET Inventory Report
Low Carbon Fuel Standard (LCFS)
EnergIIZE Commercial Vehicle Project
Zero Emission Vehicle (ZEV) Infrastructure Topics
How Much Does an Electric Semi Really Cost?