Allye introduces 400 kW fast charger with second-life batteries
British company Allye Energy has unveiled the MEV, a battery-buffered fast charger for depots. The system uses complete second-life batteries from EVs and is designed to provide up to 400 kW of charging power without necessarily requiring a more powerful grid connection.
The first deliveries of the MEV are planned for the second quarter of 2027.
Image: Alllye
The Mobile Energy Vault (MEV) is designed to draw energy from an existing depot power connection and initially store it in repurposed vehicle batteries. During charging, this energy can then be delivered at significantly higher power levels. According to media reports, Allye primarily targets fleet locations where the available grid connection capacity is insufficient for conventional fast charging.
At launch, two variants are planned. The MEV200 offers 155 kWh of storage capacity, while the MEV300 provides 232 kWh. Both systems are capable of charging two vehicles simultaneously. Allye specifies a maximum DC charging power of up to 400 kW.
The technical foundation is the 800-volt architecture of the Max300 mobile battery storage system. According to the manufacturer, it supports both 400-volt and 800-volt vehicle systems. The so-called PackFlex technology enables the operation of battery packs of varying sizes, ages and cell chemistries within a single system.
Allye states that it uses complete battery packs from decommissioned electric vehicles, rather than newly produced cells. Per unit, this approach is estimated to save approximately 15 to 24 tonnes of CO₂ equivalents compared to a system using new batteries. This figure is based on the manufacturer’s calculations.
Battery storage buffers weak grid connections
The approach involves decoupling grid power and charging power. The battery system can be charged over an extended period at relatively low power from the grid and then deliver this energy to vehicles at high power for short durations.
A practical example of this approach is a project by the company at J&M Murdoch in Glasgow. According to Allye, a grid upgrade for a waste management company’s operational depot was quoted at approximately £300,000. Instead, Allye and charging provider Chargepoly installed a Max300 unit on an existing 32 A connection with 22 kW capacity. The storage system now powers a separate DC fast charger for two electric vehicles, providing around 200 kWh of energy per day, as stated by the company.
This example also highlights the limitations of the concept. While a battery storage system can enable high charging power despite a weak grid connection, it does not replace the required energy volume. The number of vehicles that can be serviced daily still depends on how much electricity can be recharged via the existing connection over several hours.
Allye argues that this solution helps avoid long waiting times for new grid connections. The company points to lead times of 18 to 36 months for new depot connections in the UK. In contrast, the MEV can be installed via industrial sockets or a fixed connection and commissioned within a few hours. The system can also be dismantled and redeployed at another depot in the event of a location change.
For operation, Allye incorporates additional safety features. The charging cables are equipped with cut monitoring, forensic markings and quick-release mechanisms to facilitate faster replacement of damaged cables. Cameras monitor charging stations and cables. Inside the storage system, features such as pyrotechnic fuses, gas detection and fire barriers between battery packs are included.
The MEV remains a stationary system at the depot. In contrast, the technically related Max300 is designed for mobility and can be used, for example, as a replacement for diesel generators or to power additional charging points. Pricing for the MEV starts at £70,000. Alternatively, Allye offers the system as “EV Charging as a Service” from £1,900 per month for the MEV200. The first deliveries are scheduled for the second quarter of 2027.
With its battery storage solution, Allye addresses a well-known challenge in fleet electrification. Often, the issue is not a fundamental lack of energy at a site but rather a limitation in the immediately available grid connection capacity. Whether a battery-buffered fast charger is economically viable compared to a grid upgrade depends heavily on the location, charging profile, existing connection and the costs of potential grid reinforcement.