• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 716 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ28Z610 Design and Pack Resistance Parameter Clarification

B-A
Intellectual 720 points

Hello,

I am wanting to know how the design resistance and pack resistance values for IT Cfg in Gas Gauging differ if I am using the gas gauge in a single cell application. By observation, the SOC that I see through bqStudio achieves 100% a little too soon before the charge is complete. Since I am using a single cell, I would expect the design resistance and the pack resistance to mean the same thing (I would expect a higher pack resistance for a two cell setup). Could someone explain as much as possible how these are used so I may understand how adjusting them affects the SOC estimation?

Thank you for your time,

Blake

  • 0
    TI__Guru* 76230 points

    Hi Blake

    Design resistance should be set to the 4 grid point of your Ra table. Pack resistance doesn't mean the pack resistance of your cell. Pls keep that as default except there will be sufficient trace resistance between your celll and your system. See attached app note on how to make the measurements for pack resistance. Page 5. Although this was written for a different device, the idea is the same.

    pack_system_resistance_bq30z554-R1_Turbo Apps-02-21-13.pdf

    If you want to hold off the device from reporting 100%  early, set your charge termination to use taper current and taper voltage conditions and then set the RSOCL flag. See trm. This will hold off SOC at 99% until charge termination based on taper current and taper voltage is met.

    thanks

    Onyx