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BMS. Active cell Balance. LiFePo4 with PowerPump™ Balancing

Antonio José
Prodigy 45 points
Other Parts Discussed in Thread: BQ76PL102, BQ78PL114, BQ78PL116, BQ78350-R1, BQ76930, BQWIZARD, BQ78350, BQ76PL536A, EMB1499Q, EMB1428Q, BQ34Z100-G1

Active balancing circuit 8 LiFePO4 cells (75Ah). PowerPump balance. BMS.

Dear fellow Texas Instrument:

I am contacting you because I would like to design a new BMS that monitor and control in serial 8 cell of LiFePO4,
With the following characteristics:
* Individual Cell: 3.2V and 75Ah.
* 8 cell pack: 25V and 75Ah.

We have been studying different configurations of Active Balancing and most liked us to keep the PowerPump,
Integrated chips described for bq76pl102 bq78pl114 and Texas Instrument.
*(PowerPump technology transfers charge efficiently from cell to cell during all operating).

We would create our first test PCB soon, but we would like to confirm that the design is possible.

Our batteries LiFePo4 have much capacity and voltage curve is very flat.

Do you think that the bq78pl114, bq78pl116 bq76pl102 chips could serve us?

Do We should use other chips to control the Active Balancing of our 8 LiFePo4 cells?

Thank you very much for your time.
Best regards.

  • Prodigy 45 points

    Failed to Update bq78pl114 with firmware to bq78pl114s12.

    We are designing a BMS with active balancing and monitoring voltages and temperatures 8-cell battery but are getting an error message "Comunication error hardware" when I use bqWizard 3.1.0 and USB-GPIO conect to access bq78PL114 on the PCB board that I designed.

    Reference Schematic of circuit: Figure 1 :(BMS bq78pl114 and bq76pl102)

    And we have the following error when updating the firewall FW5000: Figure 2: 

    Any suggestion is greatly appreciated.

    Antonio.

  • in reply to Antonio José
    TI__Guru 73830 points
    Antonio,
    I am sorry that we have not responded to your inquiry, but it was posted to the wrong forum and we have not seen it. The PL114 will not work very well with LiFePO4 cells. The PL116 works better, but we still do not recommend using it with LiFePO4 cells. We recommend using the bq78350-R1 and bq76930 for this application.

    As far as upgrading the PL114 to the PL114-S12, did you see the Firmware Upgrade Procedure in the Documentation directory in the bqWizard directory on your computer. I have updated the firmware successfully on this device before, but it has been a few years.

    Tom
  • in reply to ThomasCosby
    Prodigy 45 points

    Dear thomas,

    Nice to know your answer.

    I would like to design three BMS that control and monitor 3 packs 8-cell LiFePO4 of 3.2V and 70Ah each cell.

    Important: These BMS must meet the following characteristics:

    • Active 8-cell balancing. (Ej: PowerPump)

    • Voltage Monitoring

    • Temperature Monitoring.

    • Communication. Ej: SMBus (I2C).

    By these characteristics, I have chosen these chips: BQ78PL116RGZT, BQ78PL114RGZT and BQ76PL102RGTT.

    I have designed a circuit as shown in Figure 1, and would like to work well (“I do not rule a new design of BMS with other different chips in the future, but now I want to work this design because I think that it is best suited to our needs”).

    If you believe that other chips are more suited for our characteristics, please let us know.

     

    New Design: I have developed a circuit with active balancing by induction very similar to chips (bq78pl116EVM) how in the Figure 2 and Figure 3.

     

    Also I have installed the BqWizard 3 on the PC and have updated the USB-GPIO adapter (2.0.19), Figure 4 with adress: (0x16=0022). The BMS is connected to the emulator batteries (Power source of 28V and 8 resistors 10 OHM) and the USB-GPIO.

    Tests performed:

    1)      Verify the voltage at VLDO1 = 2.5V and VLDO2-V2=2,5V, after connect the chip bq78pl114 or bq78pl116 with the pc by USB-GPIO active bqwizard.

    But the bqwizard not recognize the chip (Figure 5 or Figure 6).

    Also I loaded the configuration (.tmap) for 8 cell and 4 temperature sensors.

    2)       I download the update (Fw5000) but stops in the 49s (Figure 7 y Figure 8).

     

    I would like to working with this design, but I hope your recommendations in response to our desired characteristics.

    We believe that the bq78350-R1 and bq76930 chip don`t have the characteristics we look for. For example they can't do active cell balancing and not read temperatures. (Not conform to the design of characteristics).

    Please, I need your help and advice.

    Thank you,

    Best Regards.

    Antonio José Blanco.

  • in reply to Antonio José
    TI__Guru 73830 points
    Antonio,
    I assume that you are working with the PL114. The bqWizard program v3.1 supports this device. The bqWizard program v3.2 supports the PL116. You cannot program a PL114 device with the PL116 firmware, nor vis versa either. Unfortunately, this is a very old device that has been NRND for several years and we can no longer provide additional applications support to help with issues.
    Best regards
    Tom
  • in reply to ThomasCosby
    Prodigy 45 points
    Tom,
    Thanks for you answer,

    I know that the bq78pl114 and bq78pl116 be NRND but I need a local BMS with active cell balancing, monitor voltage and temperature.

    1) You recommended us to use the chips: bq78350 and bq76930 for our application but I think they have passive balancing.
    Is it possible to perform some form of active balancing using this chips? How?

    2) I've been looking for other chips with active cell balancing at Texas Instruments. Ej: (The BQ76PL536A with EMB1428Q and EMB1499Q).
    Alternatively, are there any other products which could be paired with our characteristics to perform active balance, and also monitor voltage and temperature?

    Thanks for you help,
    Best regards,
    Antonio José.
  • in reply to Antonio José
    TI__Guru 73830 points
    Active cell balancing cannot be added to the bq78350 chipset. You can use the bq34z100-G1 along with one of the AFE devices that you mentioned. They can provide balancing, monitoring and protection and the -G1 can provide gauging.