Why Is Ionity Adding Big Batteries to Its Fast-Charging Parks?
Ionity has switched on its first battery-buffered EV charging park in Germany and plans the same approach for dozens of European sites in 2027. What the battery solves, what is still unknown and what drivers gain.
Europe's fast-charging networks keep running into the same wall: they have the land, the chargers and the customers, but not enough power from the grid. Ionity, the high-power charging network founded by a group of carmakers, is turning to a fix that is fast becoming common across the industry: a large stationary battery placed right next to the chargers. The first one is now running at its Wertheim site in Germany, and the company says roughly 50 more systems will follow across Europe in 2027.
What changed at Wertheim
The charging park sits next to an exit of the A3 motorway in Baden-Württemberg, between a fast-food restaurant and an outlet centre. Until recently it offered four charging points. Thanks to the battery, Ionity now runs six, all on Alpitronic HYC400 units, with two more on an ABB charger rated at up to 350 kW said to be coming soon.
The company shared the technical details with "electrive": the storage comes from Chinese supplier Sungrow, consists of four modules totalling 1,028 kWh, and can deliver up to 500 kW. The batteries live in separate cabinets on the site rather than inside the chargers. An energy management system decides, moment by moment, how much power comes from the grid, how much from storage and how much goes to each car.
Why a battery instead of a bigger grid connection
The short answer is time. According to Ionity, upgrading a medium-voltage grid connection in Germany can take up to three years. The battery tops itself up from the grid during quiet hours at modest power and releases that energy when several cars are plugged in at once. That lets the site deliver more power at peak times than its existing connection could manage alone.
Ionity lists further benefits too: lower demand peaks, which are expensive for operators; storing solar power where panels exist; and, later on, possible income from grid services or energy trading. Christoph Strecker, Ionity's head of rollout, told "electrive" that the goal is not simply to build more charging points but to put the right infrastructure in the right places and keep improving the charging experience.
The plan for 2027
Ionity wants around 50 battery systems at charging parks across Europe in 2027, with more than 20 MWh of combined capacity. Simple division gives an average of about 400 kWh per site, well below Wertheim, which suggests each installation will be sized to its location. The company has not published the list of sites or target countries yet.
Ionity is not alone. BYD already uses storage at its ultra-fast charging stations, and Tesla installed a huge battery at its largest Supercharger site, as "Frandroid" points out. What stands out with Ionity is its current preference for external batteries, which can feed chargers from different hardware makers.
What we still do not know
The announcement says nothing about price per kWh or about faster charging for an individual car. There is no independent data yet on how the system performs in real use, for example on a busy holiday weekend when the battery could drain faster than it refills. The cost of the programme and the cell chemistry have not been disclosed.
What it means for drivers
For anyone taking an EV on a long trip through Germany, Austria or beyond, the practical upside is simpler than the technology: more charging points, sooner, at sites that would otherwise have waited years for a grid upgrade. That should mean shorter queues on busy weekends and holidays, exactly when motorway chargers are under the most pressure.
Do not expect cheaper charging just because a battery is on site, though; Ionity has made no such promise. The usual long-trip advice still applies: check free bays and the current price in the app before you arrive, and always keep a backup charger on your route. If Wertheim works as planned, expect more operators to copy the idea wherever grid connections lag behind demand.
