Proterra, who as one of the first to introduce its roof-fast charging system (proprietary one, for a 10-minute recharge - see photo above) is now turning to SAE J3105 standard (OppCharge - see photo below).

Electric bus (Nova Bus) at the OppCharge overhead fast charging station

Previously, in 2016, Proterra opened patents covering its solution.

The new Proterra Catalyst buses will be offered with:

  • SAE J1772 CCS combo (IEC Type 1) inlet
  • SAE J3105 Overhead Charging Standard
The SAE J3105 will enable sending of up to 500 kW of power, while the J1772 Combo will be used for 60 or 125 kW charging.

Read Also - Los Angeles Department of Transportation Orders 25 Proterra Electric Buses

According to Proterra, buses will be ready for bi-directional, vehicle-to-grid power flow (V2G), for smart-grid purposes.

"Across North America, cities, counties and transit agencies are announcing bold, zero-emission fleet goals. The development of universal technology standards will accelerate this transition, and Proterra is actively working to promote interoperability across technology platforms. Accordingly, all Proterra buses utilize the SAE J1772 CCS (IEC Type 1) standard for plug-in charging, and newer models of Proterra Catalyst® vehicles will now be fully compatible with the emerging SAE J3105 standard for overhead charging.

To supply the best charging options for the industry, Proterra is introducing a new suite of high power DC chargers that comply with these standards. The three new Proterra® Power Control Systems range from 60kW-500kW and are compatible with J1772 CCS plug-in as well as J3105 inverted and roof-mounted overhead charging systems. The chargers will also utilize de facto industry-standard for communication, Open Charge Point Protocol (OCPP 1.6). Proterra's new charging systems are capable of bi-directional, vehicle-to-grid power flow (V2G), enabling the chargers to be smart-grid ready to maximize the energy management capability of an entire bus fleet. Powering up a Catalyst bus is now as simple as connecting to a Proterra charger or other standards-based charging system."

"Standardized EV charging will inform future infrastructure decisions and fleet-wide electrification strategies. Proterra's new charging systems can charge transit fleets today and well into the future, with a range of power levels that can easily scale as infrastructure needs grow, both in-depot and on-route. The Proterra 60kW Power Control System is ideal for fleets with longer available charge times at the depot. Recharge time is approximately six hours for an E2 Catalyst utilizing a J1772-CCS plug-in connection. Fleets with high uptime requirements will benefit most from the Proterra 125kW Power Control System. Operators can simply plug in the charger to achieve a full charge in under three hours at the depot, with a standard E2 battery configuration.  The 500kW Power Control System works best for fleets with extended operating hours and high mileage requirements, such as 24-hour circulators. This 500kW system delivers fast overhead charging on-route or at the depot, utilizing the J3105 overhead connection standard, and can recharge up to 38 miles in 10 minutes, depending on battery configuration.

New pantograph-style options will join Proterra's available charging solutions for overhead charging. Proterra is collaborating with Schunk Carbon Technology, a world-class developer of overhead charging hardware for battery-electric vehicles, to introduce these new systems to its customers."

"Proterra and Schunk Carbon Technology will work together to further develop standards-based, lightweight, state-of-the-art, scalable fleet charging infrastructure for on-route or in-depot charging, that can flexibly support dozens to hundreds to thousands of heavy-duty electric vehicles, utilizing standard overhead pantograph systems offered by Schunk Carbon Technology."

David Carr, Facilities and Fleet Manager at RTC Washoe in Reno said:

"With vehicle agnostic charging, we have peace of mind that our electric bus fleet infrastructure investments are future-proof. Scalable, interoperable charging infrastructure supports our long-term mission to sustainably serve Reno and our neighbors, by providing innovative and cost-saving solutions that ensure clean, reliable transit today and for years to come."

Robert Averkamp President Schunk Carbon Technology US. said:

"We're thrilled to collaborate with Proterra and bring large-scale fleet charging for electric vehicles to market in North America. We've had strong traction in Europe to date equipping the largest electric bus fleet with our roof charging pantograph technology,"

Ryan Popple, Proterra CEO said:

"As more fleets embark on 100 percent electrification, we're committed to providing a seamless transition that leverages open and universal standards and empowers our customers to effectively scale with confidence. By leveraging common charging standards for electric buses, the transit industry will avoid vendor lock-in and de-risk infrastructure investments, ultimately accelerating mass adoption of EVs."

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