The unique concept of battery-buffered high-performance charging by ADS-TEC Energy GmbH from Nürtingen has arrived in the heart of Berlin. At the Aral petrol station in Holzmarktstraße, between Alexanderplatz and Ostbahnhof, the market leader in the petrol station business is supplementing its traditional fuel range with high-performance electricity from a small square box, the ChargeBox. The station is specially designed for limited grid capacities, such as here in the city, because it is normally not possible in the 400-volt distribution grid in the low voltage to offer high charging power for charging e-vehicles within minutes.

What is special about the ChargeBox?

In addition to two separate charging columns, the ChargeBox from ADS-TEC Energy has a battery storage system that can be connected directly to the normal power-limited electricity grid. Aral installed the ChargeBox station in October 2020 as part of its new Mobilty Hub, making it the first filling station in Berlin to rely on the innovation from Baden-Württemberg.

In order to integrate it flexibly into the respective location, the charging columns can be installed up to 100 metres away from the storage box. Up to 320 kilowatts can be charged at one column. If two vehicles are charging in parallel, the charging power is divided in half. "We have set a benchmark with our Supercharger. Worldwide, more than 1000 charging points are already in use at power-limited locations where fast charging would otherwise not be possible. Our customers appreciate our systems because they are efficient, flexible to use and highly convenient. They are made for the urban environment," says CEO Thomas Speidel of ADS-TEC Energy.

What is the challenge of ultra-fast charging versus slow charging?

The challenge with fast charging stations is basically that a lot of energy has to be provided in a short time. Therefore, ultra-fast charging usually requires a large connection to the powerful medium-voltage grid. However, the Aral filling station is located in the municipal low-voltage grid, which was not designed for e-mobility at the time. A power connection like the one from Aral in Berlin usually only has a low connected load of around 50 to 100 kilowatts. With ADS-TEC Energy's storage-buffered fast-charging technology, e-vehicles are nevertheless charged with up to 320 kilowatts of DC direct current without having to upgrade the grid connection.

How does the ChargeBox work?

The two slim charging columns draw their high energetic power from the battery storage system specially developed for this purpose. The ChargeBox was connected directly to the ordinary power grid, where it permanently charges slowly and at low power like a power bank. This stored energy is then delivered to e-vehicles on demand at high power and within minutes. The vehicle always determines how fast it can charge, which varies depending on the condition of the vehicle battery. The ChargeBox always delivers the maximum power that a vehicle requires.

The network is spared and does not need to be expanded either.

The decisive advantage of the ChargeBox is that the charging process takes place within the battery system and the high power does not have to be drawn from the grid. In this way, the ChargeBox eliminates the need for complex grid upgrades with large transformer stations, which not only mean higher costs and long approval times, but also require much more space. This is not available in many places like here in Berlin. The ChargeBox, on the other hand, can be installed directly and promptly. In addition, a larger grid connection generates permanent running costs in the form of high fees.

An investment in the future

Aral has more in mind with the buffer battery than just the operation of the charging station. For example, there are long-term plans in Berlin to also use self-generated energy in order to become more independent of the electricity grid with the entire location in Holzmarkstraße.

With its high output of 320 kilowatts, the station is already "future-ready". By way of comparison, Porsche's most powerful e-vehicle currently has a peak output of around 270 kilowatts. Last but not least, the entire system was extensively and fully certified in accredited laboratories and meets all relevant standards and guidelines - an important basis for safe and long-term operation.

Optimal charging solution for the city

Despite the enormous charging power, the system is quiet and blends aesthetically and inconspicuously into the urban environment. On a footprint of around 1.2 square metres, there is room for everything that would otherwise require an area almost ten times as large. This compactness in relation to performance was awarded a prize by the international pv magazine in 2019 and is unique in the world to date. Recharging a 100-kilometre range takes just a few minutes and filling up with electricity takes around 20-30 minutes, depending on the type of vehicle. At Aral, this time can be ideally used for a coffee break or a quick purchase at the Rewe To Go shop.

Battery-buffered ultra-fast chargers as a key to the success of the mobility transition

With the new Mobility Hub, Aral is actively shaping the modern mobility of the future. "In the centre of Berlin, we are testing a comprehensive, forward-looking range of CO2-saving mobility options in customer operations for the first time at an Aral filling station. It ranges from mobility sharing and a battery exchange machine to connections to public transport. The technological heart is the two ultra-fast charging points, which are supplied by a buffer battery. With this first expansion stage of the "microgrid", we can also offer ultra-fast charging in places where the local power grid does not provide the technical or commercial prerequisites," explains Alexander Junge, Electrification Director Germany at bp.