A car battery that can face -40°C? Sodium-ion takes a step closer

A car battery has to do its job on the worst morning of the year, not just in comfortable laboratory conditions. That is one reason battery makers are paying close attention to a recent sodium-ion test result from Clarios: its partners have validated cold-cranking performance down to -40°C.

It is an eye-catching number, but it needs a little context. This is not a claim that cars will soon run on salt instead of petrol, or that sodium-ion will replace every lithium-ion battery in an electric vehicle. Clarios is developing the technology for future low-voltage and high-power applications, including the demanding electrical systems used across passenger vehicles, commercial vehicles and other machinery.

The result comes from Clarios’s sodium-ion programme with Swedish battery specialist Altris and European manufacturer InoBat. Alongside the cold-weather work, the partners have carried out customer evaluations across automotive, heavy-duty and off-highway applications. They are now preparing for pilot-scale learning and small-series production, a step beyond promising prototypes but not yet mass-market production.

European Partnerships and Scaling to Production

That progress also puts fresh attention on the engineering needed around a battery. In Timișoara, Romania, Clarios is deepening its ties in Europe in a separate partnership with automotive engineering company Piaxo. Its local team, now nearly fifty strong, works across software, systems engineering and validation. Its new facilities bring engineers and a development and testing laboratory together as the two companies work on advanced low-voltage systems, including battery management technology.

The -40°C barrier that has been broken is part of the Clarios, Altris and InoBat sodium-ion programme. Its importance lies in the fact that it marks the start of the move towards industrialisation of this Next Gen sustainable battery technology. The Clarios and Piaxo partnership is part of the wider effort to develop and test the increasingly complex systems that modern vehicles rely on.

For drivers, the appeal is straightforward: a battery needs to deliver power reliably when conditions are least forgiving. For manufacturers, the challenge is harder. They have to prove a new chemistry under real operating demands, then work out how to make it consistently and at scale. The -40°C test does not mean that work is finished. It does suggest that sodium-ion has moved another step out of the lab and into industrial production as evidenced by Clarios announcing its new partnership with Piaxo for scaling up its R&D facilities in Europe for low-voltage systems.