BQ76952: BQ7695204PFBR- Monitoring Issues

Ning Li

Part Number: BQ76952

Customer feedback BQ76952 Monitoring 16 sets of batteries, 6 battery packs, then found the following problems:

1.The battery voltage was originally 3.2V, but suddenly the read data changed to about 1V, and it returned to normal after a few seconds，about 100ms MCU will read the data of BQ76952

2. The battery voltage was originally 3.2V, but suddenly the read data changed to about 3.6V, and it returned to normal after a few seconds,about 100ms MCU will read the data of BQ76952

3.The customer has carried out AB test, and the problems mentioned above will still recur, and the repetition time of the failure phenomenon is not certain, sometimes more than 10 hours, sometimes more than 24Hour

4.Every time the battery pack has a problem, it is irregular

Can you pls help to check those problems？

2620.BCU GD32从控.pdf

over 3 years ago

0 Caleb Perez over 3 years ago

TI__Genius 11795 points

Hey Ning,

I noticed on your schematic that you don't have a filtering capacitor on VC0, and that your C56 capacitor is not connected to ground. A possible issue could be noise on the cell input pin. Could collect the voltage at the VCx pin at the time of voltage error to see if the voltage on the pin is the same as the voltage being read by the AFE?. Measure voltage at cell and at VCx pin.

Also, check to see if cell balancing is active while the voltage error is occurring.

Thanks,
Caleb

0 Ning Li over 3 years ago in reply to Caleb Perez

Intellectual 760 points

Hi Caleb,

The client modified the schematic as you suggested,VC0 and VC1 conncet 220nF filtering capacitor to ground，but still found first cell voltage have suddenly 3.2V change to 1V and after 6 seconds will be normal.Below show the test data and modified schematic，pls kindly help to check.

从控原理图.pdf