Battery Management System – All you need to know!


Battery management means managing your battery charge so it doesn’t get too low or too high. It helps to prevent expensive repairs to the battery before there is any malfunction. It manages the battery charge and keeps the device within a safe operating range when the vehicle is active.

The detection of battery type, voltages, temperature, capacity, state of charge, power consumption, remaining running time, charging, cycles, and other parameters are among the battery characteristics to be monitored. Battery Management System is a hardware and software suite that stores and uses charge information from your vehicle’s battery to optimize charge delivery and maximize runtime capacity. Batteries are a type of energy storage device. Just like gasoline, batteries must be charged up to deliver their full capacity. However, unlike gasoline, batteries don’t burn completely when used up; instead they lose some charge until they are recharged. This lets you utilize them over longer periods of time before having to buy another battery. Most smart phones and digital devices contain small lithium-ion batteries; these can be recharged using a special adapter. Vehicle batteries are the most expensive component of an electric car. We can expect improvements in battery technology and a reduction in cost. As well as some new technologies such as super capacitors that can help charge your batteries much faster than current rechargeable.

EV buses have reduced battery costs and expand recharging capacity for public transport. They are cleaner and quieter than petrol-powered buses, making them ideal for quieter urban areas and city centre runs. The charging system is the heart of an electric vehicle. The cost of a battery usually depends on its capacity and the kind of charger you use. The job of battery management systems is to make the best use of the residual energy in a battery. To avoid overloading the batteries, BMS systems safeguard them from deep discharge and over-voltage, both of which are caused by severe fast charging and extreme high discharge current. In the case of multi-cell batteries, the battery management system additionally includes a cell balancing function to ensure that all battery cells have the same charging and discharging needs.

Battery balancing and cell monitoring: 

Battery balancing is a method used by the auto industry to ensure that cars are running as efficiently as possible with minimal loss of power. When you drive long distances with the key in the ignition, you are applying voltage to the battery. When batteries are fully charged, they can give maximum power. But when they are discharged quickly, they lose this voltage. This balancing process is performed using sensors in the car that constantly monitor the voltage on the battery and apply it according to how much charge remains. Four main functions that are essential for monitoring are cell voltage measurement, temperature measurement, cell balancing, and isolated communication to the main battery controller. These are software application, everything is monitors under software. A communication network is setup with the battery and a controller using UART communication protocol. Every input from the battery is closely observed and necessary action is taken if any problem occurs.

Battery charging system:

The battery charging system is designed to recharge the high voltage battery from the alternating current grid. In automobiles, the technology is known as the on-board charging unit. Battery pack voltage tends to become uniform at around 450 V with a trend towards higher voltages as battery capacity and energy efficiency of the electric components increase. This allows for quicker charging times and lighter cabling within the car. The move toward fast charging has an influence on the power range required, thus new system designs are trending toward 11 kW or even up to 22 kW. One of the most basic functions of a battery charger is to regulate battery voltage and current without exceeding temperature limits. This necessitates a control loop that measures the battery parameters (voltage, current, and temperature) and controls the PWM duty cycle that drives the external power network.

Condition sensing: 

Aside from current/voltage and temperature monitoring, sophisticated analytics for thermal, electrical, and mechanical strain are done at the pack level. Highly accurate pressure sensing allows for the observation of probable cell housing expansion as a result of an overload/charge state, as well as the detection of mechanical effects on the mechanical structure of the battery pack. Sensing evaporated CO2 from the cell’s electrolyte as a result of cell age or overstress might be utilized to monitor battery health. Combining and analyzing the readings of the various condition

sensors enables the identification of illegal pack manipulations, such as cell alteration or replacement by measuring.

Control and Communication: 

Microcontrollers ensure that communication between the off-board chargers and the BEV or PHEV being charged is safe. They also safeguard the vehicle’s communication network. These sophisticated microcontrollers have all of the necessary safety and security features for OBC applications. For electro mobility applications, the embedded hardware security model (HSM) provides secure communications with an optimized peripheral set that includes ADCs and timers.

Current and Isolation Monitoring:  

Monitoring isolation is critical for high-voltage batteries. The voltage of the high-voltage DC+/- lines is continually monitored against the pack’s mechanical casing and the surrounding chassis, in addition to short circuit and overload current monitoring. The availability of high-performance current sensors enables the use of accurate current measurements in the context of Coulomb counting, state-of-charge, depth-of-discharge computation in battery monitoring, or improved impedance spectroscopy in battery diagnostics.

Thermal control and management

Active thermal control is a critical component of modern Li-Ion battery packs because cell temperature for charging must be kept between 0 and 45°C and for discharging between -20 and 60°C; operation outside of these ranges results in accelerated ageing, reduced capacity, or even total battery damage.

Market share

According to The global battery management system market size is estimated to grow from USD 5.2 billion in 2019 to USD 12.6 billion by 2024, at a CAGR of 19.5%. The growth of this market is expected to be driven by the growing trend of electric vehicles, increasing requirement of battery monitoring in renewable energy systems, and need for effective electric grid management