SDAA084 April   2026 BQ25856-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2How to Extend the Life of Supercapacitors
    1. 2.1 Effects of Voltage
    2. 2.2 Effects of Current
    3. 2.3 Effects of Temperature
  6. 3Supercapacitor ESR and Capacitance
    1. 3.1 Estimating Capacitor Capacitance and ESR
    2. 3.2 Measuring Supercapacitor Health With The BQ25856-Q1
    3. 3.3 Estimating the Capacitance and ESR in Reverse Mode
  7. 4Summary
  8. 5Appendix - Example MCU Code for the BQ25858-Q1
  9. 6References

2.2 Effects of Current

Large amounts of current sinking or sourcing to a supercapacitor will cause internal heating. Sink or source currents exceeding the supercapacitor's specification decrease the lifespan of the device. The BQ2575X and BQ2585X-Q1 family have discharge current limits to limit the total sourcing currents of the supercapacitor through the IBAT_REV register. The BQ2575X and BQ2585X-Q1 family also have charge current settings to accurately regulate the current into the supercapacitor.