May 8, 2009 Automotive engineering facilities in the UK have joined forces to design a system which allows conventional delivery vans to be cheaply converted to run in a zero-emissions, all-electric mode for urban use. The ADDZEV (affordable add-on zero emissions vehicle) system was developed using a standard Vauxhall Combo van, retaining the existing conventional front-wheel-drive (FWD) system and an adding an electric drive in parallel for the rear wheels. The vehicle can operate with just front wheel drive powered by the internal combustion engine or can turn off the petrol engine and run with rear wheel drive under electric power only.
Battery only range is expected to be 12 miles (20 km) and the battery can be charged either from the mains or through regenerative braking. For regenerative braking, some of the kinetic energy of the vehicle is transferred to the battery when it stops, more like a conventional hybrid.
ADDZEV uses a valve-regulated lead-acid battery rather than the nickel metal hydride (NiMH) or lithium ion (LiIon) technology used in conventional electric vehicles. It delivers 240V and has a capacity of 20A/hours. The innovative spiral-wound valve-regulated lead acid batteries used in the project are supplied by project co-leader and sponsor The Advanced Lead Acid Battery Consortium (ALABC). A lead acid battery was chosen over LiIon or NiMH because it's cheap - though significantly heavier, it costs a quarter to a fifth of the price of NiMH alternatives. ALABC tested the battery by replacing the 4.8 kWh NiMH battery in a Honda Insight with their own lead acid battery. It has so far run for 100,000 miles (161,000 km) with no problems.
The ADDZEV system uses twin liquid-cooled motors with a maximum power of 100 kW and peak torque of 350 Nm (more than double the 125 Nm available from the standard petrol motor), mounted in a discrete sub-frame under the rear floor of the vehicle. Electric only drive has been limited to propel the vehicle at a speeds up to 37mph (60 kmh).
The kit has the potential to turn any FWD combustion engined car into a 4WD plug-in hybrid with all the benefits of range extending regeneration and up to four times the torque of a standard petrol car. The technology, which can be retro-fitted into a wide range of vehicles, could reduce operating costs by 40% compared to operation on traditional fossil fuels alone.
Paul Evans
Via: Cranfield University.
