Optimal Electric Vehicles LLC (Optimal-EV) and Proterra have partnered to leverage Proterra’s battery technology and charging systems for the development of the industry’s first all-electric S1LF low-floor cutaway shuttle bus for the North American market.

Optimal-EV’s S1LF will utilize Proterra’s battery systems, which have industry-leading energy density for maximum range, a flexible design to fit within a wide variety of vehicles, and rigorous pack level validation to ensure safe and durable vehicle operation. The Proterra® battery system powering the S1LF will feature 113 kWh of energy capacity and an all-electric, zero-emission drive system that is designed to enable more than 125 miles of driving range. The vehicle can fully charge in about two hours with optional DC fast charging. The all-electric S1LF integrates a Ford E450 chassis platform, which has been fully optimized for the vehicle body. The all-electric S1LF will feature a gross vehicle weight rating (GVWR) of 14,500 pounds, with no reduction in carrying capacity.

The S1LF will debut at the APTA EXPO 2021 and be available for commercial purchase in 2021. The S1LF is the first of several planned commercial electric vehicles from Optimal-EV for use in a variety of applications.

Through the Proterra Powered™ program, Proterra and Optimal-EV collaborated to determine the right size, shape, and performance of the battery system for the S1LF vehicle. Proterra Powered leverages Proterra’s EV technology and expertise to help commercial vehicle manufacturers electrify their vehicles. As an OEM that uses its own battery technology to power its fleet of heavy-duty electric transit buses, Proterra brings more than a decade of experience manufacturing, testing, and delivering EVs. To date, Proterra Powered has helped world-class OEMs like Thomas Built Bus, Van Hool, and FCCC introduce 100% battery-electric vehicles that are powered by Proterra electric vehicle technology.

The S1LF integrates 33 years of Optimal’s automotive design and CAE (Computer Aided Engineering) optimization and validation expertise, culminating in safe, reliable, and durable automotive grade products with the efficiency and performance of a factory-installed, fully integrated electric power system. Optimal’s low-floor design, which is made possible by the innovative packaging of battery-electric propulsion, allows for ultra-low 11-inch step-in height and quick deployment of an ADA-compliant accessibility ramp without the need for the added complexity of a kneeling suspension.