A military vehicle is designed to perform specific missions, not serve as an environmental showcase. But the CERV (Clandestine Extended Range Vehicle), which was featured at the Chicago Auto Show by the Army’s Tank Automotive Research and Development Engineering Center (TARDEC), is designed to satisfy multipurpose military requirements, while benefiting from civilian-like technology, too.
The CERV is a diesel/electric-drive vehicle, so it’s in the same development stage as some automotive designs. It was engineered and built for TARDEC by Quantum Technologies, an alternate energy systems development company. The range in engine-off electric drive (the clandestine or silent mode) is 5-12 mi (8-19 km) using a dual pack (6 kW·h total rating) of E-One Moli Energy cylindrical lithium-ion batteries. The cells are the low-cost No. 18650 type proven in laptops, power tools, and also in Tesla cars. There is both a safety interlock and ground fault detection on the high-voltage circuit.
Despite the diesel-electric drivetrain, the CERV is a relatively lightweight, compact vehicle at just 3500 lb (1590 kg), 60 in (1524 mm) wide and tall, and 199 in (5055 mm) long. The package is an important characteristic for a vehicle intended for special operations, including reconnaissance, surveillance, targeting, search and rescue, including ambulance. It is the only military hybrid certified for transportation on the V-22 Osprey twin tiltrotor VTOL/STOL (vertical/short takeoff and landing), an aircraft developed for use by all four branches of the U.S. military and in a variety of assignments. Despite its light weight, the CERV can withstand 10,000 lb (4540 kg) of crush force.
The CERV is not a plug-in hybrid. Although the battery pack could be charged offboard, the primary intent is to charge it as installed in the vehicle. It uses a 50-kW motor operated by a modified 1.4-L diesel engine sourced from Ford of Europe. When the battery charge is depleted, generator power goes directly to the 100-kW motor that drives through a two-speed transmission (a specially modified version of a five-speed) and into the four-wheel-drive system. The motor and generator are prototypes built by UQM Technologies, which is supplying the motor for the electric car from automotive start-up company Coda.
The CERV can accelerate from 0-30 mph (0-48 km/h) in just 6 s, 0-60 mph (0-97 km/h) in 20 s at full GVW (gross vehicle weight), which is 6500 lb (2950 kg). The 3000-lb (1360-kg) payload includes seating for three soldiers with mission payload and personal gear, plus a standing gunner to operate a 50 caliber M-2 machine gun. Tow capacity is 5000 lb (2270 kg), and it has a winch with a 10,000 lb (4550 kg) capacity.
The vehicle has a top speed of 95 mph (152 km/h) on paved flat roads and 40 mph (64 km/h) on trails, and it can ford 21 in (530 mm) of water. It uses tires with a run-flat range of 30 mi (48 km).
Because the vehicle must be able to ford water, the underbody is sealed. The dual battery pack is cooled by an air-conditioning system solely for that purpose, as the open vehicle itself does not use A/C for passenger cooling. The batteries are installed (and removed for service) from the top of the floor and drivetrain tunnel.
Four prototype CERVs have been built, and they are undergoing evaluation by selected commands to determine suitability for the intended missions and to provide guidance for any modifications needed for final configuration.
Despite its sophistication, the CERV is considered an interim vehicle, awaiting the day when a fuel-cell powertrain can be used.