Sally Bailey, UK Head of Electric Vehicle Charging, Vestel Mobility
As the UK accelerates its transition to electric vehicles (EVs), charging speed remains a critical factor in determining how seamlessly EVs can integrate into both business operations and broader transport infrastructure.
The challenge is twofold: supporting the infrastructure needed for faster charging while managing the demands placed on local grids. It’s a technical tightrope of balancing power, performance, and practicality, and it sits at the heart of how the UK’s EV ecosystem will evolve in the years ahead.
Yet delivering on those expectations is not as simple as plugging in and powering up. Unlike internal combustion engine (ICE) vehicles, EV charging speed is influenced by a complex mix of factors across charger type, battery chemistry, vehicle software, ambient temperature, and, crucially, grid capacity. These variables interact in ways that make real-world charging outcomes far more nuanced than EV brochure specs or Charge Point Operators might suggest.
The AC vs DC Divide
At the core of EV charging is the distinction between AC (alternating current) and DC (direct current) charging. The UK’s grid supplies AC power, but EV batteries operate on DC, meaning AC charging requires the vehicle’s onboard charger to convert electricity before it reaches the battery. This process introduces conversion losses, typically in the form of heat, and limits the effective charging speed to 7kW to 22kW.
DC chargers bypass the vehicle’s onboard system and deliver power directly to the battery at much higher rates. Public DC chargers at motorway services can typically deliver 100kW or more, with ultra-rapid chargers now pushing well beyond 150kW. For many EV cars, this can equate to an 80% charge in under 45 minutes, ideal for long journeys or quick fleet turnarounds.
Yet, even this high-speed solution is not without caveats. Battery temperature is a critical factor in charge speed. Lithium-ion batteries operate optimally within a narrow temperature range. In cold conditions below about 5°C, chemical reactions slow, reducing the mobility of lithium ions and increasing resistance within the battery. This can lead to longer charge times and higher energy losses. Conversely, in hot conditions, typically above 35°C, batteries face risks of thermal degradation, necessitating controlled (read: slowed) charging to avoid damage.
Modern EVs use battery management systems (BMS) and thermal control technologies to mitigate these effects, from pre-conditioning strategies that warm batteries before charging to active cooling systems that dissipate excess heat. Even with these measures, planning infrastructure or forecasting energy loads throughout the seasons, particularly at sites with high traffic volumes or diverse vehicle usage profiles, remains challenging.
The Grid Challenge
Perhaps the most pressing concern for the energy management sector is grid capacity. Fast charging, especially in clusters like motorway service stations or fleet terminals, can place enormous strain on local distribution networks. Load balancing technologies are incorporated into all DC charging hardware, dynamically allocating power across chargers based on real-time demand. This can help alleviate the pressure on the grid, but the net result is highly variable, and often much slower EV charge speeds at busy times.
Long-term solutions lie in strategic grid upgrades and, in some cases, the deployment of local battery energy storage systems (BESS). These systems can store energy during off-peak times and release it to support peak charging loads, acting as a buffer between demand and grid supply. For larger charger sites, remote locations or multi-location networks, BESS and integrated renewable local energy generation represent a practical tool for smoothing energy demand and enhancing resilience.
Innovations in battery design, including silicon-based anodes and solid-state cells, promise to reduce EV charging times and extend battery lifespan. Meanwhile, advances in smart grid integration, predictive demand analytics, and renewable energy sourcing will help ensure that the EV charging infrastructure of tomorrow is faster, greener, and more efficient.
Demanding times
That shift is ever more critical as we transition heavy haulage and public service vehicles (PSVs) to electric power. The combination of massive batteries and the need to minimise downtime of the vehicle exacerbates grid pressure. This is not a ‘future’ problem either. Vestel Mobility works closely with innovators in the UK, like Ryze Power’s PSV conversion team, and we are launching one of Europe’s first 1MW DC chargers for heavy transport later this year.
Energy and grid optimisation for higher EV charge speeds requires a holistic understanding of energy flow, technology, infrastructure limits, and user behaviour. It’s not just about installing faster chargers; it’s about creating intelligent systems that balance speed with sustainability, cost, and grid stability.
At Vestel Mobility, we see the demand for charge speed as a catalyst for innovation across the energy sector. By embracing the complexity and investing in smart, scalable solutions, energy leaders can help drive the UK’s transition to a cleaner, electrified future, where EVs of all sizes charge faster, fleets move smarter, and the grid works more efficiently for everyone.
This article appeared in the October 2025 issue of Energy Manager magazine. Subscribe here.
