Battery Management
Systems

A Battery Management System gets the best out of lithium-ion battery systems, ensuring multilevel electronic safety, longer lifespan, and improved performance. Our BMS measures all battery parameters, interrupts the current when required, and optimizes performance during charging and discharging. For devices and vehicles reliant on a reliable power supply, the Battery Management System is a decisive factor in optimizing overall performance, battery lifespan, and safe operation.

A battery management system enables the safe operation of lithium-ion battery packs totaling up to 800 V, and supports various energy storage systems and multi-battery systems for large facilities. When developing an intelligent BMS battery our researchers and developers focus on feedback and monitoring aspects. A battery management system must be able to keep a keen eye on cell voltage, temperature, and the health status of batteries. Such monitoring protects batteries from adverse events such overloading or overheating, and even cuts the power circuit if required. All this means a good BMS can improve the life span and performance efficiency of each individual cell.

Based on our three BMS systems, we have developed a BMS Toolkit to respond flexibly to our customers’ projects. We use this BMS Toolkit to simulate a real situation in the most efficient, economic, and precise way. In doing so, we consider the entire machine cycle and develop solutions accordingly which can then be customized or extended as required. With adaptations via Toolchain and ongoing analysis of the Battery Management System we adjust safety features down to the smallest detail before actual implementation. The BMS Toolkit replaces lengthy test runs in operation, ensuring seamless implementation and an uninterrupted machine cycle.

To understand how a Battery Management System optimizes battery use, let us have a look at the current generation of electric cars where lithium-ion battery packs contain between 16 and 53 kilowatt-hours of energy. For a helpful comparison, a liter of premium gasoline provides 8.8 kilowatt-hours, so a lot is asked of the battery pack. It gets much-needed help from the Battery Management System. By controlling and monitoring each individual cell, the efficiency of the battery pack is optimized in the most precise way. Indeed, the BMS measures, monitors, and controls all relevant cell parameters, from cell voltage, current and temperature to operating processes. The BMS battery pack is constantly protected from complete charging or discharging; this has a positive effect on its service life and performance. The goal of a BMS in hybrid and electric vehicles is to achieve a battery life of 10 to 15 years while retaining more than 80 percent output capacity. To achieve this goal, any smart battery system needs reliable battery management that maximizes the range, reliability, and safety of the battery pack.

It may surprise you to learn that a typical battery pack is operated in a limited State of Charge between 20 and 80 percent; only 60 percent of the capacity is used. The reason for this is safety - the limited capacity is intended primarily to protect the individual battery cells from over- or undervoltage. Small variations in cell characteristics and operating conditions can cause variations in self-discharges. A BMS can simultaneously ensure utmost safety and maximum capacity. The Battery Management System monitors each individual cell, which is why capacity can be maxed out to the operating limit without ever exceeding it. With lithium-ion batteries, this is a masterstroke because their discharge curve is incredibly flat over the operating range. The BMS must be able to detect even the smallest change in the State of Charge.

Passive cell balancing is a simple and cost-effective solution in offline operations in which the cells with a high State of Charge (SoC) are discharged. However, this discharging involves the transformation of electrical energy into heat, a process which limits the balance to a maximum of 5% of cell capacity and hence takes a little time. In active cell balancing, electrical energy is transported between the cells both when discharging during operation and when charging. The BMS supplies the weakest cell with energy from the strongest and vice versa, depending on the charge status. The biggest advantage is that less heat is generated, the equalization current is optimized, and the timing is significantly shortened. The biggest challenge here is precision - the Battery Management System must detect deviations of less than ±10 mV to avoid measurement errors and be able to perform active cell balancing.

We believe technology is the key to advanced, sustainable batteries. Our Battery Management System optimizes battery performance and drives forward our vision of sustainable and efficient use. As a partner, e.battery systems develops specific solutions based on years of experience and accumulated engineering knowledge. This includes electromobility components as well as individual prototyping, for specific requirements needs or for mass production. In projects all over the world, we have proven our competence as a partner for battery development.

In the development and production of our Battery Management Systems the keyword is reliability – where we are concerned, there are no compromises when it comes to the quality of electrical components. The core of our BMS is comprised of components from notable Austrian manufacturers, with each one contributing to our comprehensive quality standards.

In electromobility, the dynamic power requirements on the batteries are particularly subject to change. This makes an intelligent Battery Management System all the more important, while at the same time demanding a great deal: The BMS must guarantee a reliable, uninterrupted power supply in the face of extreme fluctuating power requirements. It must also do so at all temperatures, whether a tropical hot summer or a cold arctic winter. That is why, from the outset, e.battery systems is uncompromising when it comes to the quality and functionality of system-critical components. A particularly important aspect in an electric car is optimal thermal management. The Battery Management System keeps the cells in balance so that deep discharges - which could significantly shorten the battery's lifetime – do not occur. Instead, a charge protection system prevents any excess current from being supplied even during charging, and prevents the triggering of thermal instability or chemical reactions. Through intelligent control, the BMS keeps the battery in a safe range and measures all critical parameters. In addition to electromobility, other industries also benefit from the advantages of intelligent Battery Management Systems: automotive areas, communication technology, mobile consumer electronics, construction technology, and many more.