Startup rethinks EV thermal management

British startup Hydrohertz has patented a thermal management technology dubbed ‘Dectravalve’, which early testing suggests could cut electric vehicle fast-charging times by more than two-thirds while boosting battery performance and efficiency. 

It has the potential to enable vehicle manufacturers to quickly boost the appeal of electric vehicles in a cost-effective way, without waiting for next-generation battery technology to reach commercial scale. 

The innovation has drawn international attention and earned three consecutive Earthshot Prize nominations, recognising breakthroughs that help repair the planet.

Charging duration remains a major barrier to EV adoption, particularly in regions such as Australasia where long travel distances make slow charging more disruptive.

Fast charging drives temperatures up within battery cells, and once they pass about 50°C, the system is forced to slow the charge rate to avoid long-term damage.

Thermal throttling is why sessions advertised as 30 minutes frequently extend to 40 or 45 minutes in real-world conditions.

Hydrohertz contends that the real limitation is not the battery or charging hardware but the thermal management system controlling pack temperature, prompting the company to develop the Dectravalve to remove thermal weak points that trigger power tapering.

A new approach to battery cooling

At the heart of Hydrohertz’s system is the Dectravalve, a 16-position oscillating valve that combines the manifold, valves, and accumulator or coolant reservoir into one managed system.

This allows precise routing of coolant to multiple independent zones within the battery pack, including individual modules.

By managing each zone’s temperature in real time, the Dectravalve prevents hotspots, ensures consistent performance, and extends battery life.

This zoned control also enables smaller battery packs, reducing vehicle weight and production costs.

It also helps simplify a vehicle’s thermal architecture with fewer components while remaining compatible with a wide range of sensors, pumps and logic systems.

“Optimising the operating temperature of an EV battery is crucial to both its short- and long-term performance,” explained Hydrohertz chief technology officer Martyn Talbot.

“Unlike traditional systems which treat the entire pack uniformly, the Dectravalve allows for targeted heating or cooling of individual modules within the battery.

“This means it can keep every part of the battery pack at a consistent, optimum temperature, maximising the performance of the cells across the entire pack.”

Mr Talbot, who stepped down from CEO of Hydrohertz in 2025 to focus exclusively on technical development,  described the Dectravalve as “elegantly simple”.

“A single, digitally controlled unit can manage four or more cooling zones separately. With Dectravalve, each cooling zone is completely independent, so coolant flows from the pump to the battery and back again in a specific loop. There are no unwanted, efficiency-sapping, leaks of warm coolant between zones.”

He added that the zoned architecture prevents overheating in one module from influencing another.

“There is no ‘shared circuit’ where one overheated cell group could cause wider thermal contamination. 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 Dectravalve’s design also supports waste-heat recovery from motors, electronics and cabin systems, improving overall system efficiency and cabin comfort.

Independent validation shows major gains

In an ultra-fast charging test conducted with researchers from the renowned Warwick Manufacturing Group (WMG) at the University of Warwick – a leading global research and education group with deep expertise in advanced battery systems – a 100kWh lithium iron phosphate (LFP) battery pack equipped with the Dectravalve kept its hottest cell below 44.5°C while maintaining just a 2.6°C variation across the battery.

By comparison, many current EV systems see peak cell temperatures rise to around 56°C with spreads exceeding 12°C, conditions that sharply reduce charging power and extend overall charging time.

Under these controlled thermal conditions, the Dectravalve-equipped battery remained in its optimal high-power window, allowing charging to proceed without the usual thermal bottlenecks.

Hydrohertz said this stability reduced charging times by 68 per cent, enabling a 10–80 per cent charge in about 10 minutes on a 350kW DC fast charger rather than the typical 30 minutes.

“What makes this genuinely  breakthrough technology is the precision it delivers,” said Mr Talbot.

“In our testing, we kept battery cells within just 2–3°C, which translates directly into faster charging, longer battery life, and critically, enhanced safety.

“We’ve essentially created a thermal management system which thinks and responds as quickly as possible – and one that is completely agnostic to cell chemistry too.”

Efficiency, range and longevity

Because it is compatible with major EV battery chemistries, the Dectravalve can be integrated into existing packs.

Its multi-zone thermal precision also enables vehicle manufacturers to optimise battery size and weight without compromising performance. This yields the potential to reduce vehicle mass and cost while simplifying overall architecture.

Improved thermal efficiency also reduces internal energy losses, increasing real-world driving range by up to 10 per cent. Add to this the potential of smaller, lighter battery packs, total vehicle range gains may exceed 20 per cent.

Enhanced thermal stability also reduces cell stress, supporting battery-lifespan improvements of around 25 per cent, helping to shore up shaky EV resale values.

“The automotive industry has been waiting for battery technology to catch up with consumer expectations, but progress has been slow and expensive,” said Hydrohertz interim CEO Paul Arkesden, a long-time advisor and automotive executive recently appointed to guide commercial expansion and industry partnerships.

“A new chemistry can take a decade to develop and require billions in investment. What we’ve done is take a different approach – we’ve dramatically improved how existing batteries perform by perfecting the thermal management of them.

“This is a cost-effective solution that delivers game-changing results: consistent 10-minute charging, longer range, extended battery life and enhanced safety.

“For OEMs, this means better, more useable EVs now, without waiting for the next generation of battery technology. But when that technology does arrive, Dectravalve will optimise it too. The impact for both car makers and consumers is set to be transformative.”

Commercialisation

Although Hydrohetz has independently validated its claims, the Dectravalve is yet to be deployed in a production vehicle.

Early technical renderings place the unit above the battery pack, raising questions around packaging, integration and production cost – all factors that may ultimately shape which vehicles or platforms can adopt it.

Applications beyond EVs

Hydrohertz claims that the Dectravalve’s modular design and ability to dynamically manage heating, cooling or dual-use flows while eliminating complex pipework and cross-contamination makes it suitable for aviation, rail, data centres, agriculture and building climate control.