What do you think about battery management system lithium-ion

Without a central and effective control system managing the affairs around the lifespan of your electronic device batteries, providing safe operation, optimizing its performance so you can always have consistency and protecting a variety of cells inside the battery, your device effectiveness will always be the doubt.

To all these, the appreciation goes to the battery management system; you could also call it the engine/control room of the battery that regulates the functions in the device.

Lithium-ion battery cells are only able to function within their distinct operational window because of a tireless battery management system. The temperature, the voltage, and the current under the operational window work just fine with a battery management system (BMS).

Due to the location in the module or some little differences in the cells, cells often age differently, and one of the responsibilities of the battery management system is to make sure these cells are appropriately balanced regardless.

One of the components of lithium-ion is the specified temperature windows and the maximum charge and the current discharge points. Calculation and determination of the maximum charge and discharge current a module can take, are the undertakings of the battery management system. It also oversees advanced battery management systems, discreetly monitors module’s temperature and measures individual cell temperatures.

The battery management system is the power behind lithium-ion battery’s ability to be today’s energy reservoir of technology and for the future.

The Design Of A Battery Management System

Understanding the design of the system will help in providing an insight into how it works. Basically, the battery management system of lithium-ion battery is made up of many functional blocks like cell-voltage monitor, cutoff field-effect transmitters (FETs) cell-voltage balance, fuel-gauge monitors, temperature monitors, real-time clock and a state machine.

· Cell-voltage monitor

Cells are usually fixed patterns and are parallel to form a battery pack. At zero level, the charge and discharge battery pack cells are at the same rate. But when the cells begin to cycle from charge to discharge, the discharge rates in between the cells changes. · Monitoring of the cell’s voltage to a particular level will help to determine if the battery pack got charged.

· Fuel-gauge monitors

This component has the duty of keeping track of the charge going in and out of the battery pack. However, on designing a fuel gauge, various techniques are used. there are: a current-sense amplifier and analog-to-digital converter(ADC)

· Temperature monitoring

Their sensors are positioned to monitor each cell for energy storage-system. To monitor and keep track of circuit temperature, the thermistors enabled by the internal ADC voltage ensures that.

· Cutoff field-effect transmitter (FET)

The connection and isolation that exist between the load and charger only get performed thanks to the FET. The FET drivers can be made to connect to the low and high side of battery too.

· State machines

These are also known as microcontrollers; meaning that the state machine is one of the essentials of a battery management system, as they play the role of managing information gotten from the sensing circuitry.

Specifications Of Battery Management System Of A Lithium-ion Battery

The BMS of lithium-ion has proud impacts on these areas:

· Ability to detect battery temperature

· Able to spot monomeric battery voltage too,

· It can also predict insulation resistance early

· It can detect batteries operating electric current

· It can estimate a battery’s state of charge (SOC)

· To make available necessary battery data CAN1 for the entire vehicle control, BMS ensures communication with the vehicular control.

· It can also communicate with vehicular monitoring devices and can equally send battery information to display CAN2

· To safely ensure battery charge, it also communicates with the charger.

Requirements Of Battery Management System Of A Lithium-ion Battery

A complex task is in the making of a battery management system, given the specific requirements of the application and the features of the battery cells. A quick look at these requisites is therefore necessary.

Generally, a lithium-ion battery management system seeks to enable these:

· Voltage provision

A typical lithium-ion battery management system ensures the provision of at least one voltage acquisition route per cell that is serially connected.

For some automotive applications, the availability of an additional secondary in-built protection is very important, as it helps to alert the battery management system when a cell is operating outside the permitted voltage range. This it does through the aid of the programmable window comparator device the secondary protection comes with.

· Temperature provision

Finding out the exact temperature as well as where to measure a battery pack’s temperature is one of the most tasking when designing a battery management system.

Given the fact that lithium-ion batteries cannot perform well in too high or too low temperature; therefore, the precise temperature should be known to avoid plating. Taking into mind also are the three uses of temperature; which includes: · charging, discharging, and for storing.

To have all these effective in the safe operating range, the opinion(s) of the cell manufacturer should be sought.

· Current provision

In determining a dynamic state of charge (SOC) during operation, an additional method that utilizes measured current value coulomb counting should be used, with the fact that measurement for SOC determination is crucial during standstill periods.

What this method does is to integrate the current flowing into or out of the battery. However, the used current sensors must meet oppositional needs because using coulomb using can be risky at times.

Also, the sensor may be required to have the bandwidth to be able to capture current changes depending on the application.

· Communication

Because the BMS has the responsibility of communicating to complete the system, i.e., the energy management, power electronics, vehicle control unit in a car. The means of communication provides, the required speed, reliability, and robustness should always be confirmed too.

· Electromagnetic interference

Basically, all sensors appear susceptible to EMI, which means they should be given proper care. However, to curb this, power electronic components, electric machines, and other parts should be designed appropriately with EMI in mind. They should have proper EMI filtering devices like blocking capacitors and mode chokes.

Other requirements include:· Balancing,· many factors are responsible for an imbalance in the charge between serially connected cells, and the solution is to keep them minimal, so it doesn’t disturb the system’s performance.

To Wrap It Up

Battery management system remains one of the essentials and the hope for quality and satisfactory battery life optimizing. For it to remain efficient in performance, a knowledge of its offerings and capabilities has proven important.·