What type of batteries power Jouley, and how do they work?

Thomas Built Buses’ Saf-T-Liner^® C2 Jouley^® uses lithium-ion batteries made by Proterra,^® a leading manufacturer of electric batteries and drivetrains. Inside each battery pack are thousands of small-format cylindrical cells that power the bus’s components, including a 2-speed Eaton transmission and a UQM Powerphase 220 motor. As needed by the district, the batteries can be recharged either throughout the day or at the end of the day.

What is a battery management system?

Each one of Jouley’s batteries is optimized by a battery management system (BMS). The BMS is like the brain of a battery pack. It keeps tabs on many factors—like voltage, temperature and humidity—and uses that data to ensure the battery continues to operate safely and efficiently.

What are kWh, and how do they affect battery capacity?

The amount of energy a battery can hold is its capacity, which is measured in kilowatt hours (kWh). More battery capacity means more energy, which directly translates to longer range. At 226 kWh, Jouley has the largest battery capacity of any standard-model school bus.

What is operating range, and what factors can impact it?

Operating range refers to how far a bus can travel before its batteries need to be recharged. Jouley has a standard operating range of up to 138 miles, which many districts will find is sufficient to run the bus for an entire day or more before it must return to a charging station. In addition, operating range can be affected by terrain, ambient temperature, passenger load and driver behavior, such as hard acceleration or excessive idling.

What is regenerative power mode?

Regenerative power mode, which is activated when a driver takes their foot off the accelerator, utilizes braking resistance to capture the kinetic energy of an electric vehicle. By transferring this energy to the batteries, regenerative power mode can help maximize operating range. Jouley comes standard with two modes that vary the level of braking resistance.

Does the ability of Jouley’s batteries to hold a charge fade over time?

Jouley’s batteries are designed to last at least 4,000 cycles so that any change in capacity is imperceptible over the long life of the bus—unlike a cell phone battery that tends to fade over time. To put that in perspective, it is estimated that Jouley batteries could last around 11 years before battery degradation is noticeable, based on recharging the batteries twice a day during a school year. And as the Electric Bus Authority, we make it easy to recycle or find a new use for your batteries after the lifecycle of the bus.

What is the difference between AC and DC charging?

Alternating current (AC) and direct current (DC) charging differ primarily in terms of charging time. With an AC charger, most electric school buses can be partially charged in 4 to 6 hours and fully charged in 8. But with a DC fast charger, which comes standard on Jouley, buses can be charged in as little as 2 to 3 hours. Learn more about school bus batteries and charging.

Can I charge Jouley anywhere? What kind of charging port does it have?

Jouley uses a J1772 CCS Type 1 combo charge plug port, which is a DC fast charging standard in North America for medium- and heavy-duty commercial vehicles. As the industry moves to this DC charging standard, Jouley will continue to be compatible with CCS1 charger plugs. However, it’s important to remember that charger manufacturers have unique product designs, including operating system software, which could make certain chargers incompatible with Jouley.

Are electric school bus batteries safe?

Proterra batteries use ballistic-grade aluminum and undergo extensive safety testing to ensure that the small, cylindrical cells inside are protected in the event of an accident. They also utilize passive propagation resistance (PPR) for even greater safety. In the unlikely event that a battery cell experiences a thermal malfunction, the issue would not transfer to neighboring cells in the battery. Instead, it would immediately be detected by the battery management system. Learn more about battery safety in Jouley.

What kinds of safety standards should I be aware of when purchasing an electric school bus?

Jouley meets both the SAE J2929 and ISO 26262 electric vehicle safety standards. SAE J2929 is a rigorous, high-level standard that defines a minimum set of acceptable safety criteria for lithium-based rechargeable battery systems. ISO 26262 is a functional safety standard that ensures the integrity of monitoring and controlling software that protects the battery pack against the most critical hazards and failures. Going beyond these industry standards, we worked with Proterra to test Jouley and its battery packs for safe operation in extreme heat and cold as well as in situations involving impacts, vibrations and submersion. It is this commitment to rigorous testing that makes Jouley the most well-thought-out electric school bus in the industry today.

What are V2G and V2X?

V2X is short for vehicle-to-everything. It includes a wide range of use cases, such as vehicle-to-home (V2H), vehicle-to-building (V2B) and vehicle-to-grid (V2G). V2G technology can be especially helpful by supplying energy back to the power grid from the battery of an electric vehicle when it’s needed—especially during times of peak energy demand.

How can V2G save my fleet money?

V2G technology can result in savings for vehicle fleets that contain electric school buses. That’s because many energy companies and utility providers will pay school districts for storing excess energy and supplying it back to the grid during times of peak demand. V2G is a proven technology, and Jouley is ready to take advantage of it today.

How much does an electric school bus cost?

Electric school buses can cost 3 to 4 times more up-front than school buses with internal combustion engines.

However, they cost much less to operate and maintain. And as more schools use electric school buses, EV technology will continue to improve, driving down up-front bus and battery manufacturing prices even more. Many states, as well as some utility companies and service providers, offer grants, incentives or special financing to cover the initial purchase price of electric school buses—and even charging infrastructure.