AndyH
Well-known member
http://www.sae.org/mags/TBE/8920
100 mile range
55.5KWh Tesla-supplied battery packs
100 mile range
55.5KWh Tesla-supplied battery packs
Seven months after unveiling an all-electric walk-in van chassis, Freightliner Custom Chassis Corp. (FCCC) debuted a preproduction aerodynamic delivery truck with the electric powertrain.
"We recognized that we needed to do more than offer a stand-alone all-electric chassis, so we partnered with other companies to do a full vehicle that is a stark departure from the traditional boxy Class 4/5 truck," Michael Stark, Alternative Fuels/Hybrid-Electric Vehicle Project Manager at FCCC said about the next-generation medium-duty commercial truck.
The first public ride-and-drive opportunities of the all-electric truck with a flat-leaf spring front and rear suspension were for conference attendees of the 10th annual Hybrid Truck Users Forum in Dearborn, MI, in September. "We already have orders for the vehicle, and we plan to be in full production by mid-2011," Stark said.
FCCC's new electric truck is capable of a 100-mi driving range on a single charge. "That really fits very well with the typical delivery routes seen daily in urban areas," said Stark.
Tesla Motors is the supplier of the truck's three lithium-ion battery packs, each pack providing 18.5 kW·h for a total of 55.5 kW·h. According to JB Straubel, Chief Technology Officer at Tesla Motors, "The fully electric Freightliner truck is the first application of our battery technology in a commercial vehicle. Fleets are a logical next step in the electric vehicle revolution."
The batteries, packaged within the steel frame rail structure, power the preproduction truck's 120-kW peak/45-kW continuous ac induction electric motor and a single-speed (2.56:1) gearbox that engages and turns the driveshaft.
A communications gateway interprets CAN messages between the batteries, which have a Baud rate of 500 kbps, and Enova System's electronic control unit (ECU), which has a Baud rate of 250 kbps.
According to Eben Clapsaddle, Program Manager at Enova, "The gateway combines signals from all three packs into a single output to the ECU, which allows charge and discharge of the packs in parallel. The result of the combined information allows the power from the three smaller packs to be processed as a single large pack."
The ECU includes a dc-dc converter, an inverter, as well as an integrated onboard charger. According to Stark, the batteries are capable of going from depletion to full charge in six to eight hours from a 220-V, single-phase, 30-A connection.
Morgan Olson, a builder of walk-in van bodies, designed the composite panels for the electric vehicle with a GVWR of 14,000 to 19,500 lb.
According to Robert Burnham, Vice President of Engineering at Morgan Olson, "The side, rear, and roof panels are a polypropylene honeycomb core structure sandwiched between two layers of fiberglass-reinforced plastic skins. We retained the traditional all-aluminum floor structure, and the framework into which the composite side, rear, and roof panels interlock is made of aluminum extrusions."
The side doors, bulkhead, and bulkhead door in the preproduction version are aluminum. "Those parts will be evaluated for transition to composites or a combination of composites and aluminum extrusions in the production models," noted Burnham.
Scale-model wind tunnel testing has identified potential areas for aerodynamic improvement.
"Future optimization of the current design could include the addition of transparent headlamp covers to reduce drag pockets in the front and reshaping of the side mirrors," explained Burnham.
Comparison wind tunnel testing of the electric walk-in van and a conventional walk-in van is planned so the data obtained from the tests can be used to make decisions about possible future changes to the body shape, according to Burnham.
Final assembly of the truck will be at Morgan Olson's facility in Sturgis, MI, while the EV chassis will be assembled at an FCCC plant in Gaffney, SC.
According to Stark, "Our goal for the all-electric truck is have a return on investment for our customers that's in the two- to three-year time frame."
