Varta presents 21700 format cell ‘V4Drive’

After the announcement in March, the battery manufacturer Varta has presented its new large battery cell called ‘V4Drive’. The round cell in 21700 format is to be produced on a pilot line this year, but the schedule for series production has not yet been revealed.

As reported, Varta wants to be able to charge the ‘V4Drive’ battery in six minutes. However, the cells in the 21700 format (2.1 cm diameter, 7 cm long) are not to be used in electric mobility as the sole traction battery, but as a booster in premium and sports vehicles or as storage for recuperation energy in hybrid vehicles. The company sees further applications in electrified trucks with an optimised range extender or with an optimised fuel cell.

At the presentation of the ‘V4Drive’, which was broadcast online, Varta CEO Herbert Schein repeated some statements he had already made in March in an interview with the German publication Wirtschaftswoche. What is new, however, is that the “power version” of the cell is supposed to have a charging time of only six minutes. This leads to the conclusion that there will also be a cheaper standard version, although Schein did not reveal further information. Below is the announcement video, in German:

On the other hand, there were a few more details about the “power version”. Since the materials and the windings in the round cell have been optimised for a particularly low internal resistance, the cell would heat up to only 34 degrees in six minutes during a charging process. “That means there is more to it,” said Varta developer Edward Pytlick. However, Varta did not provide details on the test environment – the heating of a single cell in the laboratory would be difficult to compare with a cell integrated into a battery pack. Due to the low internal resistance, however, the heat distribution within the cell should be more homogeneous, which in turn should improve the charging performance and simplify cooling.

The round cells, which are in the same format as the cells in the Tesla Model 3 and Model Y from US production, are initially to be used in premium cars, Varta showed the animation here in a sports car. Compared to pouch or prismatic cells, the form factor is supposed to offer more flexibility in placement, and the optimised installation space and centre of gravity is particularly important in sports cars.

However, Varta left open when the cells can be mass-produced in larger quantities, and the market development for battery-electric and hybrid cars is proceeding rapidly. What is clear, however, is that production on a pilot line is to start this year.

Varta was very confident that it would be able to scale up production quickly and reliably. As Varta CTO Rainer Hald explained, they were able to transfer a lot of know-how from the ‘CoinPower’ cells. “The ‘CoinPower’ is in principle also a round cell, only here, in contrast to the 21700, the height is less than the diameter,” Hald said. “But the winding process and other manufacturing steps are very similar.” Since the production process is in the company’s own hands and many machines and tools are developed in-house, production can be ramped up in a short time, but Hald did not give a yearly figure. In the Wirtschaftswoche interview, CEO Schein had held out the prospect of 2024.

In addition to eMobility, Varta says it can also imagine using the ‘V4Drive’ in drones or power tools. There, the cells are supposed to offer twice the power with the same energy content – and also the fast-charging capability in six minutes. This could make battery-powered impact drills or electric saws more powerful, and the batteries could also be recharged over a coffee break.

With reporting by Sebastian Schaal, Germany.

Source: live-stream press release