54 When it comes to details of the desired battery specification, including chemistry, packaging efficiency is the foremost consideration at this stage, O’Flynn emphasises. “That will then drive some of the form factor and chemistry options available to us based on what we can get from the market. And then, within that space, we also need to consider ancillaries like the power distribution units, contactors, connectors and thermal management as well. So, where the key challenge is for us is being able to fit all of that into the space. “We’re not at the stage yet where we are talking specific chemistries because we’re going to be guided by the platforms we can get from the market that will enable us to meet our financial constraints first and foremost.” Higher safety standard While the inherent safety of the battery chemistry, controlled by the battery management system and the thermal management system, is a consideration for discussion with battery suppliers, crash safety is an issue about which ELM has made a key decision. “L7e doesn’t mandate any crash safety targets, whereas N1 does (N1 is an EU category covering electric vans, small trucks and light commercial vehicles under 3500 kg) , but we think it’s our duty to deliver a vehicle that drivers feel safe driving, and fleet buyers feel safe buying to put in drivers’ hands. So, we want to deliver a vehicle that meets the same level of passive safety as an N1 vehicle,” O’Flynn emphasises. “Considering what that means for battery packaging and the body structure around the battery, that’s been the main thing up to now in terms of feeding into the product architecture.” He adds, “Detailed safety concepts will be addressed in the detailed design phase with battery partners. Thermal management of the battery is considered crucial, with a preference for simpler systems to reduce complexity and potential issues. Charged issue Customer feedback indicates a preference for faster charging to minimise downtime, and the ability to use both public charging infrastructure and the chargers that logistics operators might have at their bases. The aim is to support existing AC and DC charging infrastructure, with a focus on achieving a useful amount of charge in a shorter time for AC charging and exploring options for rapid DC charging, Astheimer explains. “From the customer’s point of view, charging is linked to range and downtime. If you can charge by a significant amount in a lunch break, for example, or between rounds as you’re loading the vehicle, that may enable us to have a slightly smaller battery. They would like to be able to use public charging infrastructure where possible so as not to have to get back to the depot to plug in. So, range and charging are interlinked.” O’Flynn adds that AC and DC charging mean different things for the vehicle, bringing their own challenges. “Taking AC first, there’s a mix of what people have in their depot environments and even in the public domain. The interesting thing for us is that with the size of the battery we are talking about, we have an opportunity to add a useful amount of charge in a short time,” he says. “But at the same time, with the L7e vehicles, which typically have 48 V systems, there are still challenges with power management.” Therefore, ELM is still examining all the available options and, as with the battery, figuring out how much space the on-board chargers will take up and how much thermal management they will need. Other factors in play include whether customers can upgrade their own infrastructure from, say, 7 kW up to 22 kW, or have a greenfield site ready to accept a bank of new 22 kW chargers. There are also decisions to be made around DC charging, O’Flynn continues. “Again, we have some challenges with the vehicle BOM and the bus voltage constraints around DC charging, but we are exploring options to support rapid charging with some of our partners already,” he says. “Ideally, we are looking at 30 minutes or so to get from 20% to 80% charge to support that lunch break case.” The constraints on dimensions and mass imposed by regulations around L7e-CU vehicles are very challenging, O’Flynn notes. “They give us some very May/June 2025 | E-Mobility Engineering The driver’s cab interior emphasises durable materials, ergonomics that ease ingress/egress from either side, and a similar eye height to vulnerable road users such as cyclists and pedestrians
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