Hello,
We are currently designing an electronic board with a 4S1P Li-Ion battery pack and use a BQ3050 battery gauge. After many tests, we have tuned the gauge parameters (according to the file attached) to suit our needs (4 cells, Li-Ion, 1500 mA mean discharge current, 3000 mA charge current, 3700 mAh capacity).
After charge/discharge cycles (nearly fifty cycles per pack), the pack Full Charge Capacity (FCC) is updated and decrease from the Design Pack Capacity (3700 mAh) to a lower value. In some packs, we have a value of 200 mAh or so and in others roughly 2000 mAh. The issue is: why the full charge capacity decrease so quickly and how to re-initialize this value to the default one (The only way we find to clear all data in the gauge is to desolder and resolder all the cells from the gauge, re-calibrate and write data to data flash).
We also face an other issue when charging or discharging the battery. All goes well from 100% down to 50% or so and after a few seconds, the Relative State of Charge drops down to 7%. The same behavior is visible when charging, after an hour, the pack capacity goes from 5% to 45% and suddenly jumps to 100 % in a few seconds. Have you ever seen something like that in a battery pack and what does it means (pack health).
Thanks in advance for your answers,
Best Regards,