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BQ76930: Looking for a BMS solution

Part Number: BQ76930
Other Parts Discussed in Thread: BQ78350

Hi All, 

customer is looking for a BMS solution with the following specs: 

They use a LiFePo4 cell, but the BMS chip should be as universal as possible.

The chip should have the following characteristics:
- able to measure the voltages of the cells (8 cells in serie per each pack)
- if possible also measure the output current of the battery pack (Coulomb Counter)
Here is the real problem:
The battery pack in the normal state delivers a few amperes but for a very short time the battery can deliver up to 2500A. Is there a chip that can measure such a wide range of current?
- If possible, to measure the state of health of the cells
- various safety features:
Over-current shutdown
Short circuit shutdown
Over / under voltage shutdown
Protection when charging the pack (monitoring of charging current / voltage)

Do we have something in our catalogue for this? 

Regards,

Jon

  • the bq76930. For 8 cells standpoint, it can be configured with the bq76390. There would be a minimum of 3 cells/group. Its a monitor and protection device and has many of the features you asking for integrated into the Si. With the companion bq78350 gauging is offered based on the cell chemistry.
    At these currents, refer to the SCD and OCD threshold offered in the d/s of the device.
    I feel, sizing of the sense resistor , paralleling FETs, splitting DSG/CHG paths would be of importance.
    The CC, which an accurate 16 bit ADC (Delta Sigma Integrator) has 1LSB accuracy of ~ 8.5uV with an operating dynamic range of 200mV.
    Also, CC cannot respond to peak or instantaneous current; rather averages over 250ms.

    Since, if 2500A, does the system going to have any redundancy built into the design?