- An innovative thermal management device promises to slash charging times, boost range and minimize battery degradation in EVs.
- It’s called the Dectravalve and it can be fitted to any battery, no matter the chemistry.
- The device can independently cool or heat up to four independent battery zones with no cross-flow and a single inlet.
Keeping an electric car’s battery in the right temperature zone is essential. That’s why almost all new EVs have some sort of heating and cooling system that ensures the battery can be fast-charged safely and that it will deliver as many miles of range as possible, whatever the weather.
That said, making an efficient heat management system is not easy or cheap. Usually, an EV battery will have a cooling plate that runs above or below the modules. That’s fine for most situations, but it also means that some cells might get too hot in certain situations because they’re too far from the coolant. And if one cell is too hot, it forces the whole pack to throttle the power input or output.
Photo by: Hydrohertz
Now, though, there’s a company out there that believes it can solve this problem at a fraction of the cost of developing an all-new battery pack. It’s called the Dectravalve, and it’s made by United Kingdom-based Hydrohertz.
The compact device’s main selling point is its ability to deliver “incredibly precise” heating, cooling or energy recovery of an EV battery, according to the company. It uses a single inlet for coolant and can control up to four zones independently without having to use multiple actuator valves or complex pipework. Hydroherz claims the Dectravalve can target and isolate heating or cooling to specific zones with no cross-flow, which can significantly improve the efficiency of modern high-voltage batteries.
To put it money where its mouth is, the startup had its device independently tested by the Warwick Manufacturing Group (WMG). A 100-kilowatt-hour lithium iron phosphate (LFP) EV battery fitted with the Dectravalve was fast-charged, and the results were impressive. The hottest cell of the pack did not exceed 112.1 degrees Fahrenheit (44.5 degrees Celsius), while the temperature difference across the pack was just 36.5°F (2.6°C).
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Source: Hydrohertz
By comparison, typical EV batteries can go as hot as 132.8°F (56°C) when being pushed to the limit, but that usually results in power throttling to protect the cells from damage. In the real world, this means charging stops take longer.
Hydrohertz claims its device can change that without having to re-engineer the entire pack. During testing, the Dectravalve showed that charging times can be slashed by up to 68%, which translates to roughly 10-minute charging sessions instead of 30-minute ones.
Keeping an EV battery at the right temperature, irrespective of the ambient weather, also helps to improve driving range, with the UK-based startup claiming a bump of up to 10%. Battery life is also improved because there’s less stress at the cell level in the long run, so degradation should be slowed compared to conventional thermal management systems.
“With Dectravalve, there is no ‘shared circuit’ where one overheated cell group could cause wider thermal contamination,” said Martyn Talbot, chief technical officer at Hydrohertz. “This stops there being a thermal ‘domino effect’ where hotspots quickly spread, and also ensures that each section of the battery receives exactly the cooling it needs. The result is a clean, controlled thermal environment right across the pack, with zero compromise or crossover.”
Talbot, who has nearly two decades of hands-on industry experience as an electrical and mechanical engineer, works alongside Paul Arkesden, who was recently appointed chief executive officer. Arkesden previously held the roles of Senior Vice President of Engineering at Singer Vehicle Design and Head of Engineering at McLaren Automotive, where he was responsible for developing the P1 hypercar powertrain.
It all sounds really interesting, but it hinges on car manufacturers’ willingness to adopt a device like this. It’s not easy, but it can happen. Just look at Yasa–its axial flux motors were so impressive that Mercedes-Benz scooped up the startup and made it a wholly owned subsidiary.
