Onyx
Slate 
Ideal for use in
- Commercial Transit
- School Buses
- Medium- and Heavy-Duty Vehicles
Onyx Slate
Built for the demands of the road, Onyx Slate powers zero-emission transit, trucks, and buses with superior performance and reliability.
The Proterra Onyx Slate features a flat battery configuration designed for longer, larger commercial vehicles, offering flexible installation options below the frame rails, within them, or on the vehicle roof.
The Onyx Slate series features two models, each offering a streamlined solution ideal for larger vehicles with height constraints and high on-road mileage.
Onyx Slate
S1-15
Highest energy Slate battery, made for mounting below vehicle frames or on the rooftop
Energy
123 / 127 kWh
Voltage
669 / 652 V
Weight
715kg
Length
2802mm
Width
860mm
Height
175mm
Energy
123 / 127 kWh
Voltage
669 / 652 V
Weight
715kg
Length
2802mm
Width
860mm
Height
175mm
Onyx Slate
H1-15
Strategically designed to fit between frame rails in commercial vehicles
Energy
82 / 85 kWh
Voltage
664V
Weight
500 / 492kg
Length
2802mm
Width
620mm
Height
175mm
Energy
82 / 85 kWh
Voltage
664V
Weight
500 / 492kg
Length
2802mm
Width
620mm
Height
175mm
Onyx Slate
H1-5
Strategically designed for applications with space constraints
Energy
27 / 28 kWh
Voltage
223 / 217 V
Weight
175 / 172 kg
Length
1042 mm
Width
620 mm
Height
175 mm
Energy
27 / 28 kWh
Voltage
223 / 217 V
Weight
175 / 172 kg
Length
1042 mm
Width
620 mm
Height
175 mm
The Onyx battery delivers confidence, performance, and efficiency.
Strategic Design
Flat, modular packs integrate seamlessly with the vehicle for balanced weight distribution without compromising operational capacity.
Rugged Durability
Built with ruggedized aluminum housings that shield each pack from impact, vibration, and extreme environments, these batteries maintain reliable performance.
Proven Safety
Every Proterra battery is tested and certified to meet or exceed UN38.3, ECE R100.03, and SAE J2929 safety protocols for heavy-duty applications.
Operational Efficiency
Exceeding 178 Wh/kg gravimetric energy density, our batteries extend range and increase payload capacity without compromising performance.
Compact Construction
With volumetric density reaching 300 Wh/L, our packs deliver maximum energy in minimal space, preserving room for cargo and passengers.
American Innovation
Designed in California. Manufactured in South Carolina. Creating batteries for everything from school buses to heavy-duty port equipment nationwide. Buy America and BABA compliant.
Interested in integrating the Onyx Slate?
We're ready to power your shift to zero emissions.
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