L7 Drive’s solution significantly extends battery life cycle and usability

L7 Drive Oy’s path has led from new electric vehicle design to developing IoT energy solutions. Its target customers are specially telecom and car industry companies. Those enable efficient use of battery cells safely and in more cost efficiently than before. Additionally, the solutions cover intelligent battery drive monitoring and management systems.

L7 Drive began operations in 2011 with the goal of developing a lightweight L7-class LEV (Light Electric Vehicle), for intra-urban logistics.

”Together with an automotive company we got quite far in developing an electric vehicle. We went through almost all the possible commercial and technical details of the vehicle. It was not a good time to develop a completely new electric vehicle, and we were not able to raise additional funding for the project. Fortunately!” says Pentti Bruun, CEO of L7 Drive.

The group that developed the electric vehicle started to consider, which core competences created in the project could be the base for other new business. The team had seen, how complex the power train and battery pack in particular were, and how that brought big challenges to their development.

”Efficient, economic and long-lasting battery usage was a challenge for all electric vehicles. We had already developed our idea for solving battery usage challenges, and it was completely different from what our competitors had. We wanted to build a battery package of only parallel-connected battery cells as we could get rid of using a cumbersome battery management system,” Bruun explains.

The most common solution is to connect 3.2-3.7 volt lithium cells in series. The application voltage requirement defines, how many of those cells are needed. The challenge is that when battery cells are connected in series, the worst cell determines the usability of the series. The situation is the same as in the Christmas tree light sets. If one lamps breaks, none of the other lamps are lit.

L7 Drive took a different approach. ”In our solution all the cells are connected in parallel. With a DC/DC converter the voltage of the battery package is raised exactly to the needed level, exactly at the right time. Battery cells are automatically in balance with each other and no expensive and complicated battery management systems are needed. Energy is used more economically and battery pack last in use for a longer time.”

Pentti Bruun - L7 Drive
Pentti Bruun

Solution in use already in telecommunications industry

The company’s first target customers are in automotive and telecommunications industries. L7 Drive’s power backup solution is in use for example in Nokia’s LuxTurrim5G project, where the solution ensures uninterrupted power supply in the 5G nano station test network, at Nokia Campus in Espoo.

The solution consists of battery package connected in parallel, a patented DC/DC converter, user interfaces for the web solution, and a cloud service. All the data can be monitored and analyzed in real time, and the whole system management bases on the data.

”We have also developed a so-called Virtual Power Plant functionality, with which even the smallest 5G nano station backup energy sources can be pooled and controlled in real time as a single large energy source. In this way the power grid can be balanced efficiently, economically, and CO2-free, ” Bruun summarizes.

IoT Forge provided invaluable support and speed to product development

L7 Drive’s team was interested in understanding, how the existing smart solution and systems could be used for fleet management. How the data from the stadardized CAN (Control Area Network) gateway could be uploaded to the cloud, and how it could be used for different use cases, for example in remote car locking or unlocking.

IoT Forge became a partner for L7 Drive’s development project, which progressed quickly thanks to close co-operation and good project planning. First discussions were held in March 2020, the planning was kicked off in April and the first protos were ready for field tests in eight weeks.

”We didn’t face any insurmountable challenges, but the size of the voltage range required some re-design. If the voltage commonly used is 12-48 volts in these types of applications, the requirements for vehicles were that the device should be able to take up to 100 volts without it breaking. Also, we needed to find a solution with which the data from CAN gateway could be uploaded to the cloud. The data management also needed to be as cost efficient as possible,” Bruun tells.

Together with IoT Forge circuit board design was reviewed, modeling and different types of measurements were made.

”All the members of the IoT Forge team are top experts in their field. Their extensive knowledge of technology, processes, market needs and customer needs is world-class,” Bruun praises the team. ”They are easily approachable, and they give you the right tips, challenges and questions. With them we found new perspectives and avoided a lot of unnecessary work, which is often part of an R&D project.”

Additionally, IoT Forge offers a top-class range of machines and equipment. In particular, L7 Drive utilized PCB milling and measuring equipment to test and measure the performance of its modem.

L7 Drive has already piloted its products with potential customers, and the feedback has been very good. With few customer commercial negotiations are already underway.

”We have managed to design a product that meets the existing needs. We can offer a cost-efficient communications device, which suits the current demand. It works well with our battery solution, supporting sales as well. The interest is strong.”

L7 Drive has protected its key technologies with patents. It has already left six patent applications. Out of those it has already been granted three patents, including one essential patent.

According to Bruun, the company plans to systematically expand its IPR portfolio with new patents. ”Patenting is an important part of our strategy, even though it costs a lot. We need to assess carefully, for which inventions patents are sought.”

Company information

L7 Drive Ltd is a clean technology company designing and engineering leading edge smart energy subsystem technologies

Our expertise in power electronics optimization, through the application of our proprietary control technology, enables new levels of performance without sacrificing safety, reliability and cost that the industry demands.

L7 Drive’s core is an innovative power electronics technology that can be employed in a wide variety of electric powered platforms.

Founded: in 2011

Founders: Pentti Bruun, Pasi Haikola, Daniel Salonen, Mika Koskimies, Mika Laakso ja Simo Heikkinen

L7 Drive has six employees. It actively uses also a network of subcontracters in its operations.

Products: intelligent energy management systems.

Head office in Espoo, sites in Helsinki and Karjalohja.