43 E-Mobility Engineering | September/October 2025 The Battery Show Europe | Show report pyrotechnic piston driving a sharpedged punch made of a hard material to cut a blank out of the copper busbar, while proprietary arc-quenching technology handles the resulting 50,000 Kelvin plasma. While the CB100 can switch energies of up to 60 joules, its larger CB1000-2 sibling cuts off up to 3500 joules in around 0.6 ms, which means handling power of about 12 MW. The engineering challenges are formidable. Materials must withstand extreme mechanical stresses while preventing electrical reconnection, even if a damaged vehicle is moved. Triggering comes from either BMSs or crash sensors, with strict 1.75 A/12 V activation requirements ensuring reliability. brand group showed its extra-long busbars, developed to meet the growing need for robust power distribution in larger, more powerful EVs. brand’s busbars measure up to 2.53 m in length, and are designed to handle currents as high as 800 A in heavy-duty EVs. These busbars connect charging ports to battery systems (rather than forming intra-module links) and must withstand strict mechanical and electrical demands. “Bending such lengths requires specialised machinery,” explains Jörg Ruhose of brand group. Post-bending, spark testing ensures insulation integrity, which is critical given the busbars’ tight packaging tolerances and exposure to torsional stresses in service. Material innovation is also important, particularly in forming strong connections. brand has engineered laser-welded butt joints for copper-to-copper connections, using compacted braids for flexibility. More challenging are copper-to-aluminium interfaces where oxide layers typically hinder reliability. “We’ve solved this with a proprietary method,” says Ruhose. The company also demonstrates multiaxis bending capabilities, including twists, although the applications for these remain niche, Ruhose notes, and most requirements are for double busbars for charging systems, with spacer elements controlling precise separation. BorgWarner’s Cascadia Motion highlighted some of its iM-425 integrated drive modules for commercial vehicles, on-highway, off-highway, defence and marine applications. The iM-425 (Inverter + Motor), is a compact, high-torque motor/generator designed for heavyduty e-mobility applications such as Class 8 trucks, mining/off-highway vehicles, and generators. “This is all about contact tips that reduce resistance and improve switching capabilities.” The company’s global manufacturing footprint – with facilities in the UK, Lithuania, India and China – supports OEMs that require localised supply chains, Crew adds. Albright’s contactors are designed to integrate seamlessly with battery management systems (BMSs), using mechanically linked auxiliary contacts to provide accurate position feedback, which is crucial for maintaining system integrity where milliseconds matter. Astotec presented its pyrotechnic circuit breakers designed to isolate batteries during crashes or thermal runaway events. The Austrian specialist’s latest product, the CB100 mid-pack breaker, takes a surgical approach. Instead of disconnecting the entire battery, the breaker can isolate just the compromised section, explains Astotec’s Gabriel Szabo. “This results in lower cut-off currents and it makes life easier for both the manufacturer and the vehicle owner because you only have to exchange the damaged part.” These innovations reduce repair costs while maintaining safety, particularly valuable for high-voltage systems up to 1000 V. The breaker achieves disconnection in under 2 ms using a Albright’s HV500F is part of a new family of high-voltage contactors capable of handling high energies, suppressing arcing and interfacing with BMS computers (Image courtesy of the author) Increasingly large EVs mean larger battery packs that must be connected to inverters and charge ports with very long busbars, such as this 2.3 m, 800 V item from brand group (Image courtesy of the author)
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