What affects the EV charge rate?

This article was first published as a case study in the Green Finance Institute and Zapmap Insights paper Demystifying Utilisation, 2026 Update.

Designing hubs to maximise power delivery

A typical Osprey charging hub today comprises eight ultra-rapid charging bays, served by CCS2 connectors that can each deliver up to 300kW. To cover potential peak charging at this hub, a connection size of 1MVA is typically secured from the grid.

To optimise power delivery, the Osprey hub centralises all power modules in stacks that can then be drawn on by any individual EV charger’s connectors to deliver the power the vehicles are asking for in real time across the hub. This is called dynamic load balancing. Without this, available power would be tied up in individual devices and only made available to the adjacent bay, or even shared from one EV charger across two bays, to the detriment of other vehicles at the hub if a slowercharging car is in that bay.

The charge point management system (CPMS) running the EV chargers is just as important as the hardware set up. Osprey Iris is Osprey’s proprietary software platform, continually developed in-house. Owning this gives a high level of control and visibility over the set up of EV chargers, and ultimately the customer experience. For example, setting up how dual-connector EV Chargers optimise power across two bays; ensuring firmware updates are carried out swiftly in coordination with the charger manufacturer; and quickly and remotely identifying and fixing any power delivery issues such as a faulty power module. 

As a whole, Osprey sets up hubs to maximise power delivery to vehicles as they need it in real time, whilst maintaining high visibility and control over the hub experience, to the benefit of customers and kWh sold. 

At these hubs, what affects the charge rate customers get?

Fundamentally, it is the vehicle that determines the charge rate, up to the maximum that the EV charger can deliver, managed by the car’s battery management system (BMS). Different vehicles have different battery architecture, either 400V or 800V, and differing associated peak charging power rates that they can accept from the EV charger.

For example, the popular 400V MG 4 has a peak charging power of around 120kW whilst the high spec Tesla Model 3 has a peak charging power of 250kW. For the electric cars sold in 2025, the average peak charge power was 145kW.

In addition to the car’s specification, the BMS takes into account the battery state-of-charge, battery temperature and ambient temperature to manage the ramp up in charge rate and the peak charge rate, and the step down in charge rate towards the end of the charge differs between cars, resulting in a unique charge curve each time. It’s also worth noting that, to protect the battery, even if all the power in the world were available, cars usually only pull their peak charge rate for a couple of minutes.

A better measure of what a car might be expected to ask of an EV charger at any one time, therefore, is its actual average charge power across the charge. For the electric cars sold in 2025 the average of this actual charge rate was 101kW.

There are two ways in which the charging hub set up might limit the charge rate:

1. If the individual CCS2 connector is not able to deliver the power being asked for by the vehicle.
2. If the power available to the hub overall is not enough to cover peak charging times where demand is high across all EV chargers.

Looking at the above peak and average charge powers of new cars in 2025, the Osprey Charging Hub comfortably covers (1) with its connectors that can each deliver 150kW for 400V architecture and 300kW for 800V architecture cars, and by making the maximum power available across all connectors via dynamic load balancing (rather than e.g. two connectors sharing the 150kW of one EV charger). For a handful of cars, their absolute peak rate may not be possible, but this has a negligible impact on the overall time to charge, and therefore meeting this niche case does not justify the greater investment into higher power infrastructure.

Looking to the future, whilst average actual charging power is increasing for new cars, it is only doing so by 1-2kW on average each year, from 95kW in 2022 to 101kW in 2025. The 150kW/300kW charge points at the Osprey hub therefore continue to comfortably cover the needs of new cars.

On (2), Osprey typically secures sufficient grid capacity to cover peak charging times based on realworld data and trends, and indeed in most cases to deliver the full power promised by the site. Theoretically, if the hub was full of high spec cars in optimal battery states, all trying to pull their peak power, the 1MVA grid connection could limit the charge rate the hub can deliver to some of those cars.

However, again given the real-world charging capabilities of new cars, and the trend of this over time, including towards more mass market, lower spec vehicles, this situation remains highly theoretical and it is much more likely that rate is constrained by the car than the site, at present and in the mediumterm future.

What’s on the horizon for optimising power at Ultra-rapid hubs? 

Looking to the future, the concern facing charging networks is not the delivery of power at peak times, which is already amply covered by current available grid connections, but the cost of maintaining large grid connections on existing and new hubs, due to high fixed energy charges (standing and capacity charges). These are paid on a charging site regardless of utilisation, and have increased (on average, they are regional) over 450% in the past few years. As a result, consumer prices have also been adjusted upwards.

One of the key Government initiatives that would bring down cost of public charging, and make more charging hubs commercially viable, supporting regional roll out in particular, is funding relief or reduction of these for charge point operators.

In the meantime, on-site battery storage is an option to allow us to build a suitably large hub on a smaller connection size and therefore reduce capacity charge costs, making the project commercially viable. Use of battery can also avoid the highest non-commodity charges that networks pay at peak times, further improving the commercials.

Finally, in a minority of cases, the power needed for the large charging hub a location merits is simply not available from the grid. In these cases, Osprey are also looking to install on-site battery storage to enable a larger build on these sites that would otherwise be grid constrained and unable to deliver full power to customers.