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ElectroMotive Design goes with Ioxus ultracapacitors in emDRIVE®

Ultracapacitors can handle more than one million charge and discharge cycles and offer a longer lifespan than batteries. With a high cycle life, a high charge acceptance rate of 95 percent, wide temperature operating range and instantaneous recharge, ultracapacitors are the ideal energy storage solution for hybrid-electrical applications. Ultracapacitor technology is able to capture the high peak power levels of a regenerative braking event in a compact, low-weight package. Ultracapacitors offer a host of highly reliable solutions for hybrid-electrical applications.

Ioxus, Inc. of Oneonta, NY, a manufacturer of ultracapacitor technology for transportation, alternative energy, medical, industrial and consumer markets, is partnering with ElectroMotive Design (EMD), based in Ronkonkoma, NY,  an engineering company and manufacturer of hybrid electric conversion systems for Class 2 through 8 buses, trucks and vans. EMD is using Ioxus ultracapacitors as the primary energy storage technology in the hybrid electric technology called emDRIVE®.

Ioxus Vice President of Sales Jeff Colton says ultracapacitor cells are rugged, charge-efficient and provide the best energy storage solution for acceleration and energy recapture.

Components to the Ioxus-powered emDRIVE® system.

“The increased efficiency of the emDRIVE hybrid conversion system through the use of ultracapacitors will reduce vehicle system maintenance,” Colton says. “The associated cost reductions and quick return on initial investment have the capability to propel this particular technology toward mass adoption.”

Used in its emDRIVE hybrid conversion system, EMD General Manager Joseph Ambrosio says ultracapacitor technology dramatically enhances the operation over previously used energy storage solutions. Ambrosio says EMD selected the Ioxus 3,000F iCAP™ cell as the core energy storage solution, noting its lowest weight, lowest equivalent series resistance (ESR) and highest power density that is currently available. With the increased fuel mileage and reduced maintenance requirements, Ambrosio says many EMD customers should see a payback in two to three years.

“We use ultracapacitors as our energy storage medium in order to capture regenerative braking energy to be used later to assist the vehicle’s acceleration,” says Ambrosio. “Because ultracapacitors are highly efficient at energy recapture and storage, they are best able to handle the high power bursts we need for our hybrid conversion systems to deliver the highest fuel efficiency.”

The emDRIVE is a closed-loop parallel hybrid drive system that fits on the driveshaft between the transmission and the differential. It takes DC current from the ultracapacitor and runs it through the inverter to make AC current that runs the motor. The rotator of the electric motor provides propulsion and acceleration to the wheels, as well as helping to stop the vehicle during braking. It is a general vehicle control device that communicates electronically and operates independently.

Ambrosio says the emDRIVE system, now in beta production, is cost-effective, easy-to-install and can adapt to Class 8 buses and shuttles. Installations take less than 20 hours, with Ioxus making installation really simple as there is no maintenance involved with the ultracapacitor. The pre-production prototype Stony Brook University in Stony Brook, NY, has been running for the past year fits onto a Ford 450 chassis.

Ultracapacitors are the only technology able to capture the high peak power levels of a regenerative braking event in a compact, low-weight package. EMD’s emDRIVE, with the help of Ioxus ultracapacitors, extends the life of brake pads anywhere from 50 to 100 percent.

Ultracapacitors have a design life of 10 years, which can increase by reducing voltage and temperature. Ioxus says any increase in temperature and voltage will typically shorten design life. Most applications will use cells at a lower nominal voltage to ensure longer design life at higher temperatures.

An ultracapacitor only provides energy as its voltage decreases and absorbs energy as its voltage increases. They store much more energy than other traditional capacitors, but substantially less than batteries. However, compared to a battery’s limited operating temperature range, ultracapacitors have a great operating temperature capability, able to operate in temperatures of -40 to 65 degrees Celsius. Ultracapacitors are well suited for automotive applications whereas batteries are out of their comfort zone. BR