Battery Management
Systems

The key to intelligent battery management.

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.

What a BMS is.

You can think of a battery management system as the communications assistant of intelligent battery systems. It keeps a watchful eye on all important parameters and intervenes when needed. In order to protect the batteries, a BMS can swiftly interrupt the current flow and balance the charge. Battery management systems are required more or less everywhere where intelligent battery systems are in use, and play an indispensable role in increasing performance and prolonging battery life.

What a BMS does.

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.
  • Monitors cell voltage
    and temperatures
  • Oversees charging
    and health status
  • Offers protection from
    overheating and overloading
  • Monitors the charging status
    of each individual cell

Our Battery Management Systems:

BMS
AM 12s
ebatterysystems_forschung_und_entwicklung_batterie_50
This modular Battery Management System is ideal for applications with a high requirement for monitoring. Thanks to a slide-in plug connector, connecting with a vehicle is simple and safe when faced with possible warped or impaired points of contact.

AM BMS 12s at a glance:

  • Measures 12 cells in series

  • Equipped with 2 temperature sensors

  • Includes sleep mode to optimize power usage

  • Power levels with bidirectional activation for 40A peak and 20A continuous current

  • Pre-charge with short-circuit protection

  • Integrated current sensor

  • Analog shutdown of the output stage in case of overcurrent, overvoltage and overheating


Use and handling:

The BMS measures voltages of 1 – 4.2 V per cell and supports all common lithium technologies such as NMC, LiFePo4, LTO, etc. Computer-based monitoring software makes monitoring of the battery packs inherently manageable and user-friendly. It’s entirely up to the user which parameters of the Battery Management System are shown. Programming is simple and intuitive thanks to USB Type-C and ST-Link, and four LEDs are onboard to display (SoC) State of Charge. The BMS tested by AOI and Flying Probe is assembled using SMD technology.

Areas of application:

  • FTS

  • AGV

  • Robotics

  • Automotive

  • Scooters

  • E-Bikes


BMS
AM 30s
ebatterysystems_intelligente_batteriesysteme_04
This modular Battery Management System is ideal for applications with high mechanical loads and high currents. A combination of analog and software-based safety mechanisms makes this BMS a veritable allrounder in a wide range of use cases.

AM BMS 30s at a glance:

  • Measures up to 14 cells in series

  • 6 NTC10K temperature sensors

  • 3 analog inputs (0 - 10 V)

  • 4 digital output galvanic 2 A 130 V fuse

  • 1 digital output galvanic 1 A power box

  • 1 CAN out galvanic 125 - 1 M.

  • 1 CAN intern

  • 2 LED OUT

  • Analog current sensor (2 channel)

  • Wake-up = Taster/12 V/CAN


Environmental specifications:

  • IP class: IP40

  • EN60204 compliant

  • Operating temperature: -10 °C bis + 60 °C.

  • Storage temperature: -30 °C bis + 80 °C.

  • Humidity class F, air humidity < 85 %

  • Air-conditioned, with additional internal cooler fan


Use and handling:

In order to process signals, measurements and interface communication, the BMS is comprised of multiple master boards. There is a master for each part of the battery pack, and each part in turn may consist of several battery modules each possessing up to 14 cells. There is one slave per battery module, connected to the master via CAN and tasked with measuring and balancing the voltage and temperature of the battery cells.

Last but not least, there’s also the multi-master configuration which can coordinate multiple master sub-systems. A system master becomes the higher-level system that then controls external pre-charges and directs the other master systems.

Our BMS Toolkit.

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.
  • For automotive-specified high voltage batteries
  • Scalable solution including hardware and software
  • Determined by SoC, SoH, and SoF
  • For NMC, LFP and LTO cells
  • Equipped with voltage and high-voltage sensor technology
  • Supports parallel batteries

Our BMS Toolkit enables us to build first prototypes and small series as the basis for industrial scale-up. We can precisely customize all battery management and safety functions, including:
  • Circuit topology
  • Cell characteristics
  • Temperature characteristics
  • Discharge characteristics
  • Limits and time responses of safety functions
  • Interface with vehicle

BMS Toolkit Accessories.

Alongside the key components of the Battery Management Systems, we also offer an extensive range of accessories to make up a complete BMS kit. This includes, among others:

  • Protective covers
  • Pre-loading modules
  • Load resistors
  • Filter modules
  • Connector sets

BMS: Unbeatable Battery Power.

To understand how a Battery Management System optimizes battery use, let's 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.

BMS: Getting Maximum Potential From Each Cell.

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.

What’s the Difference Between Passive and Active Cell Balancing?

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.

Better and Higher Battery Performance.

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.
General BMS Functions:
The general BMS


  • temperature monitoring

  • voltage monitoring in each cell

  • passive balancing

  • prevents deep discharging and overloading

  • State of Charge

  • CAN interface


Specific BMS Functions:
The example customer BMS


  • BMS for up to 30 master cells

  • cell balancing up to 0.5A

  • compatible with various cell types and capacities

  • temperature range: -40 bis +60 °C

  • Determined by SoC and SoH

  • galvanic cell separation

  • PC User Interface

  • parameterization by customer is possible

  • USB-C port


  • separate MOSFET layer for higher currents

  • remote maintenance possible

  • integrated heating

  • controlled pre-heating


  • etc.


Why is cell balancing so important? Differences in cells can affect battery performance and life expectancy, as well as running costs. These differences are caused by electrochemical properties between the cells. The imbalance does neither the battery nor the device any good - which is why it’s impossible to imagine our lithium-ion batteries without a Battery Management System. The intelligent monitoring system controls and influences all relevant parameters so that the cells work uniformly and performance is optimized.

BMS Performance Features:

Maximum flexibility.

Our Battery Management Systems can be used in both mobile and stationary applications, and easily and flexibly managed through a centralized control system.

Maximum safety.

Our Battery Management System is an intelligent monitoring solution which can intervene when needed, thus substantially raising safety credentials.

Maximum adaptability.

The BMS can be adapted to a huge range of use cases, making it the ideal solution for every application.

High-grade components.

In the development and production of our Battery Management Systems the keyword is reliability – where we’re 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.

BMS in Electromobility.

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's 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.