The state of charge (SOC) is a core parameter in the implementation and development of battery management systems (BMS) which requires accurate measurement of the battery capacity and is used in the development of Evs. With the accurate measurement of the SOC using various equations and parameters, it is possible to manage the battery energy effectively to prevent it from over-charging and over-discharging. So, it is important to know the state estimation of batteries which is essential to optimizing energy management of Battery, which will result in extending life cycle, reducing cost and safeguarding the application of batteries.   The purpose of this project is to design and construct a state of charge (SOC) estimation for electric batteries using coulomb counting method. The system also displays the temperature, current, voltage and SOC values on the LCD display module.   Coulomb count method is also known as current integration method, which and calculates SOC by measuring the battery current and integrating it in time. This method measures discharging current of a battery and integrates the discharging current over time in order to estimate SOC. This is done to estimate SOC which is estimated from the discharging current and previously estimated SOC values. Coulomb count between two instants will be indeed be a good measure of energy added or removed from a battery but will represent SOC only to the extent that initial. SOC was good.   This project consists of few sensors like voltage, temperature, load of the battery using coulomb counting method for detecting the State of estimation of the Battery. PIC Microcontroller based control system takes care of sensing the SOC of the battery and values are displayed onto the LCD display module. The PIC microcontroller also takes the responsibility for displaying the measured voltage, current, temperature and SOC of battery onto the LCD. The system also provides audible alerts when the parameters go beyond the threshold limit using buzzer module.

 

The major building blocks of this project are:

1. Regulated Power supply.
2. PIC Microcontroller.
3. LED Indicators.
4. LCD display
5. Buzzer
6. Temperature sensor.
7. Voltage and current sensor.

Software’s used:

1. PIC C compiler for Embedded C programming and also for dumping code in the microcontroller.
2. Express SCH for Circuit design.

     

     

Regulated power supply:  

   

 

 

Block Diagram:  

   

 

 

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