BMS consists of a few parts; monitoring SOC, monitoring health, balancing, etc. I believe every parts have its own testing procedure. For example, to test balancing we need to deliberately put one or more cells of the battery pack out of balance, only then the balancing should start.

thank you for your response.

my means it is possible to test the accuracy of the BMS. my testing requirement is SOC monitering.

SOC is an estimation, means you cannot directly validate your SOC. For me, it is reasonable if the your estimated SOC is in conform with the battery's manufacturer information; i.e. your SOC is max when the charging reached its "end-of-charging" current, the SOC is min when the battery voltage is at its minimum operating voltage.

thank you for your response.

my means SOC estimation will be based on any method that may be open circuit voltage, columb counting, impedence measurement etc.. if we developed the BMS based on impedence of the battery. that means by observing the BMS and OCV we can get the conclusion on SOC. if we bought the BMS from the m anufacturer he will quote that their BMS get an accuracy of some 5% or some.it will depend on the IC which is used in that BMS i think. but if we built The BMS as a whole SOC Estimation circuit, balancing circuitand others. how can we specifiy how accurately our complete system will perform according to our requirement. can you please share information that how we can test the whole system that this is achieving some accuracy.

How can you get the accuracy while not knowing the reference value? AFAIC the information from the manufacturer of the battery is the only reference that is available. I shall test my SOC estimation based on this reference.

On my application, I have to admit that I did not quantify the accuracy. It is acceptable for me to provide the information of SOC based on the manufacturer's data. For example, the minimum cell voltage in the datasheet is 6V. I had to ASSUME that this is at 10% SOC technically (there is still 10% of charge inside the cell), but my BMS will display 0% SOC so that the user will stop any discharging process, as it is dangerous to overdischarge. For me, if my BMS shows 0% at 6.00V, that is accurate!

Of course, i must add, a good SOC estimation will provide (to the user) close to linear relationship with the time during constant current discharge. For example, for constant current load, if it takes 10 minutes to decrease from 100% to 90%, it should take same amount of time for every 10% drop. Although we all know that the voltage drop is not linear, but the user does not have to know that. Good SOC will allow the user to estimate much time left for them to continue their usage.

thank you for your response.

yes i understood. can you please clear another doubt that.

if i am the person designing product.i have bought the BMS from the manufacturer.i will keep this BMS in my product.before that i have to test/validate my BMS(we can not completely depend on the manufacturer data i.e accuracy or other function) in order to check the manufacturer data is vaild/not. my concern is if with out testing the BMS if i kept it in the product. the end product will not work properly and in some critical application(electric vechiles) it may cause severe damage. if we test and validate the manufacturers data it is best for me iam thinking.

my request is can you please share with me that "what is the testing procedure the BMS manufacturer person will prefer to qoute their data sheet to a particular value of accuracy" if this is know i can make test according to same procedure otherwise we may get another value of accuracy that may leads to great loss.

I get your point. I think this is one of the main concern of any EV development group. To answer your request; I am sorry I do not know how BMS manufacturer get their claimed accuracy. I guess they already have a particular battery pack with precise data to begin with as their reference.

BMS need the battery data in order to work. Because of that, I cannot think any approach for us to use BMS to validate the battery data. I guess the validation of battery data has to go deep down to the electrochemistry level.

Thank you for your response. Can you please forgot my concern.

I think the bms accuracy will depend on the ic with which the bms made. But how can i make test this accuracy.

Dear can you please help and share me that how can we test the SOC estimation in general?

and one more think is it possible to design the BMS in matlab/simulink environment. if it possible can you suggest me how to make this.

share me any of the testing procedures that one can do on the BMS for its working