Hercules Readies Alpha Electric Pickup Prototypes
A modular propulsion system enables multiple driveline configurations – and non-automotive EV applications.
Hercules Electric Vehicles aims to start production of its Alpha full-size pickup truck in January 2023, but the Alpha won’t be the Detroit-based startup’s first product application. “A recreational boat gets our first deployment with the same powertrain technology, the same parts and the same software controls as the Alpha,” company founder and CEO James Breyer told SAE Media.
Modular design enables the electric propulsion system to be used across mobility sectors, noted Breyer, who launched Hercules in December 2018. Initial Alpha prototypes will test a commercially available single radial-flux e-motor rated at 160 kW (214 hp) and operating through a 10:1 gear ratio. Using the off-the-shelf motor offers “production quality at the prototype stage,” Breyer asserted.
Power-electronics calibrations enable the motor to produce 196 kW (262 hp) for production applications. A dual-motor configuration is expected to produce about 550 hp (410 kW) and a four-motor arrangement will deliver “over 1000 hp with full torque vectoring,” Breyer promised. He noted that Hercules engineers investigated in-wheel motors but were “not comfortable” to commit to the technology.
Hercules’ 30 suppliers include other startups as well as established automotive companies. An exclusive licensing agreement will equip the Alpha with a solar tonneau cover capable of generating 1.2 kW of power, Breyer claimed. Another agreement addresses the eventual replacement to the truck’s prismatic lithium-ion batteries (176 kWh total). At launch, the prismatic-type Li-ion batteries will be housed in two identical battery cases, each case packaged between the crossmembers of the body-on-frame Alpha’s chassis, one in front, one in the rear. “That’s part of the modularity – design it once, design it right, then reuse it to provide an economy of scale in an economy-of-scope business,” Breyer said.
Solid-state Li-ion batteries
A change to solid-state Li-ion batteries is possible as early as Alpha’s second production year. Hercules has an agreement with startup Prieto Battery, Inc. that covers two years of commercial exclusivity for electric pickup trucks and large SUVs. Prieto, based in Fort Collins, Colorado, has 28 issued patents covering materials, process and the architecture of its advanced “three-dimensional” solid-state Li-ion batteries.
Compared to a typical Li-ion battery’s two-dimensional structure with three layers of materials (anode, separator, cathode), Prieto’s solid-state battery is different, according to CEO Mike Rosenberg. “Because we coat the anode, electrolyte/separator and cathode on the copper foam substrate in very thin layers, the lithium ions have very short distances to move from anode to cathode,” he explained. That 3D architecture enables high power, fast charging, high energy density, better safety and extreme operating temperatures, the company claims. Prieto has demonstrated an operating range of -30° to 120° C (-22° to 248°F) in laboratory testing.
“We are targeting energy density over 1000 watt-hours per liter, which is at least 50 percent higher than any Li-ion batteries today,” Rosenberg claimed. Prieto also views its technology as an eventual replacement for the heavy lead-acid batteries that handle most EVs’ 12-volt accessory loads. “It’s possible with solid-state to reduce the battery size and attach it to another electronic module,” eliminating the separate lead-acid battery, Breyer added.
The Alpha EV’s charging hardware will follow the SAE J1772 standard. “We are partnering with Electrify America, so that will be the main DC fast-charging network that we use,” said Breyer. The truck’s 11.2-kW charger is bi-directional. “If you have an RV [recreational vehicle] or a boat, you might as well use that charger as a storage battery,” Breyer suggested.
Patents, prototypes, production
To date, Hercules has one issued patent and 14 patents pending covering software controls, safety/security and human-machine interface (HMI). An expanding range of driver voice commands is a development focus; Breyer cited trailer tow-mode engagement as one example. The truck is expected to have a towing capacity of 12,000 lb. (5443 kg).
The first batch of 20 Alpha prototypes, scheduled for completion in late 2021, will undergo vehicle dynamics, cold/hot weather and other tests. The next batch of 20 prototypes will be used for durability and manufacturability evaluations. The prototype builds will use a yet-to-be revealed global OEM’s chassis and cab; that same automaker will serve as Hercules’ contract manufacturer. Pininfarina has been retained for exterior and interior design work on the production Alpha.
At production launch, Alpha is expected to have a 350-mile (563-km) driving range with the four-motor configuration. “We did about 2500 hours of modeling to make sure that we can hit the driving range target going up a hill, down a hill, and at different masses,” said Breyer. Alpha’s peak production volume will be 15,000 units annually. “Serial production occurs once you exceed that number and since we’re buying excess manufacturing capacity, we need to stay around that number,” he explained. Starting MSRP for Alpha will be around $100,000, Breyer said.