E-Mobility Engineering 014 l InoBat Auto dossier l In Conversation: Brandon Fisher l Battery monitoring focus l Supercapacitor applications insight l Green-G ecarry digest l Lithium-sulphur batteries insight l Cell-to-pack batteries focus

Once that had been done, Green-G began searching for battery and powertrain suppliers for the first prototypes. Core development of the ecarry effectively concluded with its homologation according to the N1 and R100 certification standards in November 2021; Aretino notes that this would have finished sooner if not for the Covid pandemic. The company also concentrated heavily on ergonomics, taking a similar line to Workhorse, whose EV postal vans were built around ending the physical and psychological damage suffered by US delivery drivers of IC- engined postal vans (see EME 10, Summer 2021). Green-G therefore consulted potential operators of the ecarry as to what they needed in their ideal cabin, which meant creating a physical cabin mock-up the operators could sit in, judge, and suggest modifications for. The result of adopting these direct suggestions is that the cabin floor sits only 380 mm off the ground, minimising not just the effort needed for sanitation and logistics labourers to get in and out of the ecarry, but also the risk of accidents and injuries that stem from excessive cabin heights. The cabin’s total volume is 3.5 m 3 , to enable comfort and easy cleaning, and to prevent cramping and repetitive strain injuries common to users of small commercial vehicles. Also, the panoramic windshield and (electrically adjustable) side mirrors maximise visibility of the pedestrians that the EV might need to drive among. Resilience against the seasonal climate swings of the Mediterranean is provided through four air conditioning vents and a set of high-density resistors for electric windshield defrosting, with an LCD graphic display for viewing all the necessary health and performance parameters of the battery and powertrain as needed. A 12 V bus from the battery (via a DC-DC converter behind the cabin) supplies all the power requirements for the cabin’s systems. “The cabin has an unusual shape for a light garbage collection vehicle, but the feedback from our users is very positive – including how we’ve designed the drivetrain and the vehicle’s structure,” Aretino adds. Construction Green-G typically builds the chassis of the ecarry in-house before sending the body’s assembly to specialist companies. The chassis also includes all the powertrain components mounted behind the cabin, although Green-G gives freedom to the body assemblers to move components around if needed, for ease of maintenance or body panel installation. “We install our 400 V battery packs, a 7.2 kW onboard charger [OBC], a motor and inverter in a rear-wheel-drive configuration, as well as the cabin systems such as the display, pedals, steering wheel and so on,” Aretino says. “But we leave some empty space in and around the dash in case the body assembler wants to integrate components such as extra displays or buttons for end-users’ equipment they’ve installed.” track of about 1.32 m and a 2.5 m wheelbase, and an 8 hour expected operating time before needing to recharge. In its basic form, it has a two- seater cabin in front and a bare flatbed behind, which can be fitted with an open cargo bay (with side fenders and a tailgate) or a rear-tip dumper. The dumper can be actuated if desired using an electric power take-off. A 7.5 kW electric motor and inverter drive a helical gear pump (chosen for its quietness relative to alternative options) that in turn powers the necessary hydraulics for the dumper. More specifically, 20 litres/minute of oil is propelled at 150 bar to generate the required lifting force from a 35 litre tank. “The second major issue was the battery,” Aretino says. “When you know your EV needs to fit within a certain set of dimensions, the batteries suddenly come across as being frustratingly large. “So if you choose, say, the wrong chemistry or welding technique for your cells going in, you could soon discover that the energy you need as a minimum just doesn’t fit on your EV’s body. “For that reason, the second big exercise for our r&d process was a feasibility study lasting 6 months or so of technologies relating to battery capacities. That included simulations of tightening the energy consumption of the ecarry across different virtual environments to meet the highest feasible onboard energy storage, and so end up with the 8 hour operating time between charges.” While the ecarry is expected to take on largely refuse collection duties, it can be configured by body builders for other tasks, such as carrying pump tanks... ... and aerial platforms such as cherry pickers ...refrigeration units... Summer 2022 | E-Mobility Engineering 51 Digest | Green-G ecarry