# Proterra Catalyst

The Proterra Catalyst is a battery-electric low-floor transit bus that was built by Proterra from 2014 to 2020. The second generation of Proterra's battery-electric buses, it succeeded the earlier EcoRide as the company's flagship product.

## History

In 2014 Proterra introduced the Catalyst, a fast-charge 100% electric bus to replace the EcoRide BE35. The bus was built on the EcoRide's design and engineering and delivered a longer, lighter and more fuel-efficient bus. The second-generation bus measures either 42 ft (12.8 m) or 36 ft (11.0 m) and weighs approximately 27,000 lb (12,000 kg). The bus is built from lightweight, durable carbon composite. The overall lower weight helps reduce wear and tear on streets. It has no tailpipe and runs virtually silent.

## Specifications

With the on-route fast charging system, the Catalyst can be operated continuously, 24/7, without the need to head to the depot for lengthy charge times. Catalyst buses equipped with the Fast Charge (FC) battery pack can charge at a rate of up to 500 kW. The company added a 35 ft (10.7 m) model of the Catalyst to its product line in October 2015.
Catalyst is a modular system, offered with two different lengths, two different drivetrains, and seven different batteries, depending on the required passenger capacity, speed (hill performance), and range, respectively.
Proterra Catalyst combinations :
| | | Drivetrain | Drivetrain | Drivetrain | Drivetrain |
| | | DuoPower | DuoPower | ProDrive | ProDrive |
| Output | Output | Peak | Continuous | Peak | Continuous |
| Output | Output | 240–510 hp 180–380 kW | 150–257 hp 112–192 kW | 245–295 hp 183–220 kW | 150–181 hp 112–135 kW |
| | | MPGe | Range | MPGe | Range |
| Battery | FC (94 kW-hr) | 26.8–27.1 mpg$_{‑US}$ 8.8–8.7 L/100 km | 67–68 mi 108–109 km | 22.0 mpg$_{‑US}$ 10.7 L/100 km | 55 mi 89 km |
| Battery | FC+ (126 kW-hr) | 25.8–26.1 mpg$_{‑US}$ 9.1–9.0 L/100 km | 86–94 mi 138–151 km | 21.5 mpg$_{‑US}$ 10.9 L/100 km | 72 mi 116 km |
| Battery | XR (220 kW-hr) | 27.9–28.1 mpg$_{‑US}$ 8.4–8.4 L/100 km | 163–164 mi 262–264 km | 23.3 mpg$_{‑US}$ 10.1 L/100 km | 136 mi 219 km |
| Battery | XR+ (330 kW-hr) | 26.8–27.1 mpg$_{‑US}$ 8.8–8.7 L/100 km | 235–238 mi 378–383 km | 22.0 mpg$_{‑US}$ 10.7 L/100 km | 193 mi 311 km |
| Battery | E2 (440 kW-hr) | 25.8–26.1 mpg$_{‑US}$ 9.1–9.0 L/100 km | 302–305 mi 486–491 km | 21.5 mpg$_{‑US}$ 10.9 L/100 km | 251 mi 404 km |
| Battery | E2+ (550 kW-hr) | 25.2 mpg$_{‑US}$ 9.3 L/100 km | 367 mi 591 km | 20.7 mpg$_{‑US}$ 11.4 L/100 km | 303 mi 488 km |
| Battery | E2 max (660 kW-hr) | 24.3 mpg$_{‑US}$ 9.7 L/100 km | 426 mi 686 km | 20.0 mpg$_{‑US}$ 11.8 L/100 km | 350 mi 560 km |
| Notes ↑ Output depends on battery type. 1 2 This battery not offered for the 35-foot Catalyst ||||||

### Drivetrains

At introduction, the Catalyst was equipped with a single electric traction motor, the UQM Technologies HD220. The HD220 was rated at 220 kW (300 hp) peak power (120 kW (160 hp) continuous) and 700 N⋅m (520 ft⋅lb) peak torque (350 N⋅m (260 ft⋅lb) continuous); a later revision, designated HD220+, increased continuous power and torque ratings to 150 kW (200 hp) and 440 N⋅m (320 ft⋅lb), respectively.
The DuoPower drivetrain was introduced in October 2017; it uses two electric traction motors and has a claimed 20% increase in efficiency compared to the original single-motor drivetrain, which was redesignated ProDrive. As ProDrive, the Catalyst was equipped with an upgraded UQM HD250 motor, which offered increased ratings of 250 kW (340 hp) peak power (150 kW (200 hp) continuous) and 900 N⋅m (660 ft⋅lb) peak torque (360 N⋅m (270 ft⋅lb) continuous). The DuoPower traction motors are permanent magnet alternating current motors manufactured by Parker Hannifin as part of their Global Vehicle Motor (GVM) series.

### Batteries

Buses equipped with the FC (Fast Charge) family of batteries are intended for circulator routes; XR (eXtended Range) battery buses are intended for intermediate-mileage routes; and E2 (Efficient Energy) battery buses are intended for high-mileage routes. The buses were initially offered with lithium-titanate battery chemistry, which Proterra redesignated the TerraVolt FC. FC batteries can be fully recharged in less than ten minutes.
The TerraVolt XR lithium nickel manganese cobalt oxide batteries were introduced in 2015 with improved range but slower charging, approximately one hour to full charge.
TerraVolt E2 batteries were introduced in 2016 with the longest range and slowest charging. The E2 battery range features a 3–5 hour charge time. E2 batteries have an energy density of 160 W-hr/kg and 260 W-hr/L, and use cells from LG Chem.
Batteries are carried under the Catalyst chassis, and use an interchangeable mounting system, so each Catalyst can hold between four and ten battery packs. The batteries can be swapped out, upgraded, or reconfigured as needs change.

### Charging

Buses can charge en route, allowing more trips and higher productivity for circulator or loop routes. One common example is to have charging stations at major transit centers. Two examples of this are the Washington Plaza Bus Terminal in New York and the Mill Woods Transit Center in Edmonton.
Charging rates range from 60 to 120 kW (using the SAE J1772 CCS ports) and from 166 to 350 kW (using a J3105 overhead fast-charger). In 2018, Proterra began offering the OppCharge (SAE J3105-1) overhead charger instead of its proprietary "blade" overhead charger.

## Replacement

On September 15, 2020, Proterra announced the replacement to the Catalyst, the ZX5. The ZX5 40' replaced the BE40 and the ZX5 35' replaced the BE35. Edmonton Transit Service was the launch customer, ordering 40 ZX5 40' buses.

## Notable operators

| Operator | Location | Model | Model Year(s) | Quantity |
| King County Metro | Seattle | BE40 | 2015 | 3 |
| DC Circulator | Washington, D.C. | BE40 | 2017 | 14 |
| NYMTA | New York City | BE40 | 2017 | 5 |
| SEPTA | Philadelphia | BE40 | 2017 | 25 |
| Toronto Transit Commission | Toronto | BE40 | 2019-2020 | 25 |
| Chicago Transit Authority | Chicago | BE40 | 2020 | 25 |

## Gallery

* The rear of the Proterra Catalyst
* A corporate-branded Catalyst testing in Washington.
* A corporate-branded Catalyst testing in Minnesota.
* A Catalyst BE40 of King County Metro
* A Catalyst BE40 of the NYMTA
* A Catalyst BE40 of DC Circulator
* A Catalyst BE40 of Santa Clara VTA
* A Catalyst BE40 bus of SEPTA
* A Catalyst BE40 of Pioneer Valley Transit Authority.
* A Catalyst BE35 of StarMetro
* A Catalyst BE40 of Chicago CTA
* Catalyst interior, looking back from forward aisle. Like other partial low-floor buses, there is a step at the rear axle for mechanical clearance.
* Catalyst driver's seat and farebox
* Catalyst instrument panel
* Additional driver's controls
* Front interior of Proterra Catalyst (MTA NYCT Spec)
* Rear interior of Proterra Catalyst (MTA NYCT Spec)
* Port Authority of New York and New Jersey Proterra Catalyst

## Competition

* New Flyer XE35 Xcelsior CHARGE
* New Flyer XE40 Xcelsior CHARGE
* BYD K9M
* Nova Bus LFSe and LFSe+