How to calculate C rate for a 3 cell battery model ?

Ive modelled a 3 cell battery model with active cell balancing logic. I dont know how to calculate the C rate of the battery while charging and discharging.

Can anyone help me with the followings

1. How to find C rate of battery model
2. How to change or modify different C rates and check with charging and discharging profile

Answer 1

[Sanju]

Hi @MAHENDRAN A,

The C rate of a battery is the rate of charge or discharge relative to its capacity. It is often denoted as a multiple of the capacity. The formula for calculating the C rate is:

Crate = I/C

where:

Crate - C rate.

I - the current (charging or discharging).

C - the capacity of the battery.

For example, if you have a battery with a capacity of 1000 mAh and you are charging it at a current of 500 mA, the C rate would be:

Crate = 500 mA/1000 mAh = 0.5 C

To modify the C rate in your battery model and check the charging and discharging profiles, follow these steps:

1. Modify the current parameter in your simulation or code to tailor it for different C rates. For instance, set the charging current to 1000 mA for a 1C charge on a 1000 mAh battery.

2. Run the simulation with the adjusted current values. Observe the charging and discharging profiles, keeping an eye on voltage, state of charge, and other relevant parameters.

3. Vary the current to explore different C rates. For example, adjust the discharging current to 2000 mA for a 2C discharge on the same battery. Repeat the process to simulate various C rate scenarios.

4. Evaluate the outcomes of the simulation to understand how the battery behaves at different C rates. Identify patterns in voltage profiles, state of charge, and other relevant metrics.

Keep in mind that the accuracy of your simulation depends on the fidelity of your battery model. If your model includes factors like internal resistance, temperature effects, and other real-world considerations, you'll get more accurate and meaningful results.

Remember to validate your simulation against real-world data if possible and ensure that your battery model accurately represents the behaviour of the actual batteries you are working with.

You can also refer to the below documentation link if required,

https://www.mathworks.com/help/simscape-battery/ug/battery-modeling-workflow.html

I hope this helps!

Thanks.

[MAHENDRAN A]

Hi,

Thanka for answering, this idea is for implenting in simscape. I've developed a battery pack model with cell balancing logic and charging it with DC supply. I've done c rate stuff also by changing resistance.

The current thing which you've told, can you give me some ideas about how I can charge the battery wth current as input.