I'd like to design a Battery Managements System board (based on TI bq40z50-R2) for my own small (2-4s) lithium battery pack, but I am still unsure how can I test it safely.
I am worried that an error in my board design or in the configuration of the bq40z50 might cause a short circuit or some other unsafe condition to the batteries.
The tests would also include batteries short circuit, undervoltage, overvoltage, overcurrent.
I was thinking of buying for the first tests a 2s or 3s commercial Lithium battery pack with protection (short circuit, overvoltage, undervoltage per cell,…) already integrated (unspecified IC).
I am unsure whether that protection circuit might interfere with the normal operation (measurement accuracy,…) of the bq40z50, invalidating the test.
I could also use stricter protection thresholds for the bq40z50: for example I'd set 4.23V for overvoltage on the bq40z50, whereas the protection IC in the commercial battery pack is set for 4.35V. This way I'd see if the bq40z50 sets the appropriate flag during an overvoltage test. During such a test, can I also use a multimeter to monitor the batteries voltage or would this also interfere with the protection ICs?
Once these first tests are done, I'd proceed using the designated batteries for my battery pack (branded 18650 Li-Ion or RC LiPo without protection IC already in them).
Could this work or do you suggest an other procedure/hardware?
Is there another way to simulate a Lithium battery without actually using one?
Thanks in advance for you help