E-Mobility Engineering 017 l ECE Doosan electric excavators dossier l In Conversation: Matt Faulks l Battery testing focus l Battery Show North America 2022 report l Ariel Hipercar digest l Cathode materials insight l Thermal management focus

powerful excavators,” says Thijs Van Hal, COO of ECE. “At the time, we didn’t think there was much of a market for larger excavators, but in 2019 customers started querying directly if we could electrify some of Doosan’s bigger models, principally because the emissions rules for construction projects looked like they were starting to change. “For instance, by 2025, emissions- producing cars and trucks won’t be allowed in many European city centres, and by 2030 there will be widespread bans on diesel-powered excavators in city centres.” Given Staad Group’s experience and inventory of the larger diesel- powered Doosan machines that customers wanted electrified, ECE had easy access to copious data on key powertrain constraints, such as the kinds of duties the vehicles performed and the rates of fuel consumption they exhibited during such duties. By analysing such metrics over the 200-or-so Doosan DX165Ws and DX300LCs that Staad has in operation, ECE was able to set targets that the two vehicles’ electric powertrains would need to achieve in areas such as voltage, current, onboard stored energy, and e-motor shaft speed and power. “Important goals included both machines needing to run for 8 hours between charges, they needed to have swappable batteries, and in general they needed to be safe,” Van Hal says. “There were some physical constraints and targets too. For instance, we were quite sure the battery packs would need to sit where the diesel engines had previously been installed, with some additional modifications to ensure sufficient counterweighting against the movements of the digger arms, and to keep the centre of gravity the same as in the IC engine-powered versions. “While running simulations in AutoCAD to determine the kinds of components we’d need to hit these targets, we started looking for suppliers of batteries and electric motors. We agreed the sale of the first units in late 2019, which were to be supplied in 2020.” The first half of 2020 was spent largely on selecting battery and electric drive systems, as well as integrating them into the two excavators. The summer and autumn through to the December were spent running tests to analyse well as provide a fit with the operating and maintenance procedures on construction sites, in particular how batteries are used, managed and handled. The company’s engineering philosophy therefore begins with numerous application-critical end points in mind, making it a useful study in practical EV digger design and execution. Electrifying Doosan’s excavators ECE’s first work on an electrified excavator began in 2018, which soon after resulted in the all-electric Doosan DX19. This was a small excavator that allowed the Dutch company to begin gathering and gauging interest in emissions-free systems for demolition jobs in indoor spaces, where ventilation is insufficient for conventional diesel- or LNG-powered systems. “It also meant we could start looking for partners and suppliers capable of shipping enough components for short production runs of the mini-excavator, in preparation for supplying larger quantities of more The DX165W is a smaller construction EV than the DX300LC, weighing in at 17 t and carrying 280 kWh of battery energy compared with the DX300LC’s 420 kWh January/February 2023 | E-Mobility Engineering 21 Dossier | ECE electric Doosan DX165W and DX300LC