• Battery power from Saxony.

  • Battery power from Saxony.

    • 28. October 2015
    • E-Mobility
    • Photos: Benjamin Tafel
    • Text: Walther Wuttke

    In Kamenz, the home town of the playwright Lessing near Dresden, intensive work has been continuing on the centrepiece of all electromobility, the battery, for the last three years. Flexible, modular and expansive. The latest development by ACCUMOTIVE could soon catch the interest of house-owners as well.

    Kamenz plays an extraordinarily important role in Daimler’s Green Technology strategy. This municipality near Dresden is where the batteries are produced without which the electrically-powered Daimler models would not move a single metre. In the industrial area named “Am Ochsenberg”, around 230 employees on a site of over 20,000 square metres work on the ACCUMOTIVE production lines and the future of electromobility. Since production commenced in 2012, they have produced over 70,000 batteries for the different electric and hybrid models.

    “We are able to produce all types of battery in Kamenz, and will also be supplying the batteries for the smart electric drive and the company’s hybrid models,” says Frank Blome, General Manager of ACCUMOTIVE. Production in Kamenz is part of Daimler’s “Electric Trio”, which also includes the research and development facility in Nabern on the edge of the Swabian Alb region and cell development by Li-Tec Battery a stone’s throw from the battery production plant. “We now have the necessary expertise from cell development right up to production of the finished battery,” says Blome. And: “There are not many automobile manufacturers who can do that.”


    The production capacity will expand over the next three years, Blome explains. To cater for this expansion the production area is set to double in size, and new production lines are being built for gradual integration into the overall processes. Daimler will invest around € 100 million in this Saxon location to further affirm its commitment to electromobility. This is because the plans of the developers at Daimler envisage the intensive electrification of the powertrain. “In less than two years we will have ten plug-in models on the roads, on average one every four months,” the Daimler Executive Board member for development, Thomas Weber, recently stated in an interview.

    There will be no alternative to electric mobility

    Chief engineer Jürgen Schenk gives a forecast of range, charging time and driving pleasure with electric vehicle models.

    Alongside conventional internal combustion engines, the various electric drives are playing an ever more important role. 'In developing our drives, we are proceeding on three fronts. Apart from continuously optimising our conventional drives, we are developing hybrid technology, including plug-in hybrids, as well as all-electric vehicles. We are not confining ourselves to certain model series, but are looking at the complete range from smart to S-Class,' explains Jürgen Schenk, Chief Engineer for Electric Vehicles at Daimler.

    As far as developers are concerned, this approach signifies an extra task: future models must be designed to allow easy electrification without sacrificing any of the typical Mercedes-Benz qualities. The spectrum extends from simple hybridisation, i.e. the interaction of internal combustion engine and electric motor, to the combination of electric and hybrid drive in plug-in hybrids to full electrification. This trend will also benefit in the near future from range optimisation, because, 'in the coming years,' says Schenk, 'battery technology will undergo further development. Every year, we see an around eight percent improvement, which means that, by the end of this decade, we'll have a range well above 400 kilometres.'

    For Daimler, the trend is clearly towards all-electric mobility, which is why there has been a deliberate decision against range extension using an internal combustion engine. There is a clearly defined allocation of roles. Customers who require a vehicle for long distances can choose from the plug-in models in the range. Also with this technology, the range will increase significantly in the coming years. 'As we refuse to impose any limitations on our customers, we're not going down the range extension route, which turns a car, for example on the motorway, into a rolling obstacle owing to the limited top speed,' says Schenk.

    Ultimately, however, the breakthrough of electric mobility will also be a question of economics. If the customer finds that electric mobility is less expensive than conventional technology, and once range (400 to 500 kilometres) and charging time (20 to 30 minutes) have been optimised, sentiment will flip in favour of electric mobility. 'We believe this is likely to happen by the end of the next decade,' says Schenk, daring to take a look into the future. With appropriate political support, it may happen even sooner, adds Schenk.

    Apart from the currently still critical issues of range and charging time – on both counts, e-cars will in the coming years close the gap on conventional models through an improved range of at least 400 kilometres and a fast-charging time of 20 minutes – the aspect of driving pleasure must not be neglected, says Schenk. 'If we can successfully bring those three elements together, there will be no alternative to electric mobility,' he confidently predicts.

    Jürgen Schenk Head of drive integration for all electric vehicles at Mercedes-Benz and smart
    Mercedes-Benz: Mr. Jürgen Schenk

    In addition to automotive batteries, Kamenz has recently started to develop and produce the new Mercedes-Benz batteries for stationary applications. According to the Head of Sales at ACCUMOTIVE, Marcus Brunner, there has been a lively demand for these since their presentation at the Intersolar show in Munich in June.


    ACCUMOTIVE is a comparatively small organisation within Daimler. Which is why close in-house cooperation is very important. “One key to our success is that we are involved in the development of lithium-ion batteries, which takes place in Nabern, at a very early stage,” says Blome. “We then produce designs, and work hand in hand with the developers to establish how a battery can be integrated into the production process.”

    Production in Kamenz is similar in form to the production of other components. The timed working stages from the cell to the finished battery take place in a calm, concentrated atmosphere. The cell is always the start of the production process. “After all the quality tests have been passed, the cell is installed to form a battery module together with ancillary units such as the cooling system,” Blome explains. The prepared cells are fed onto the compact production line, where a worker checks them for the correct cell voltage before a robot alternately stacks the cell and cell frame into a battery module with an energy content of 5.9 kWh. Three of these are required for the battery of a smart electric drive.


    Battery production always demands the utmost precision, and is strictly for specialists. After all, they are dealing with high-voltage units, and all personnel in production have undergone training in electrotechnology. For example, the individual cells are stacked in the cell frame with a positional precision of 0.3 millimetres. When the cell connector board is bolted in place at 66 points, the tightening torque is measured to a tolerance of 0.01 Nm. A helium leakage test is also carried out before the finished batteries leave the production lines, each of which covers around 300 square metres. Depending on the battery model, between 21 and 26 production stages are necessary before the battery is ready for installation in a vehicle.

    At present the main focus in Kamenz is on the production of hybrid batteries for the C and S-Class. The coming generation of the smart electric drive and future hybrid models are also to be equipped with batteries from ACCUMOTIVE. The company also has its sights firmly on the production of batteries for stationary applications, however. “Production of these Mercedes-Benz batteries is currently starting up. We use the automotive platform of our batteries and bring them into domestic households as Mercedes-Benz photovoltaic batteries,” Blome explains. Enabling anybody to take part in the energy revolution.