• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 409 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.

bq24166RGE /CHG always low

kyle sweet
Prodigy 105 points

My situation:

When I apply power to the charger IC, the /PG indicates that power is good.  The charger begins charging as indicated by the /CHG output.  My battery charges either fully or at least it is almost full.  But it continues to charge for 24 hours and probably longer.  The /CHG output NEVER goes high.

My questions:

What are some possible causes?

Riset = 392ohms, so Iset = 1.25A.  Iterm = 125mA.  It is possible that my device is consuming more than125mA while charging.  Could that cause /CHG to remain low?  I was expecting that since the power is still connected, the battery would be fully charged, BGATE would turn off the external FET leaving the battery fully charged and proving power to the system directly through the SYS output.

The data sheet refers to "charging current" but what is that exactly or where can it be measured?  Does it all flow out of the BAT or SYS terminals?

Thanks.

  • 0
    TI__Guru**** 165886 points

    As long as the battery is not damaged and termination is not disabled due to a control loop other than constant current or constant voltage being in control, then the IC should eventually terminate charging, especially if the safety timer times out. The IC has to measure the charge current below the termination current threshold for 32ms undisturbed by load transients on SYS stealing that current for 32ms in order to terminate. The other control loops kick in to reduce charge current and disable termination if your system load is too high for the input power source , the TS pin says the battery is too hot/cold or the IC internal thermal management self protects the battery.  BGATE does not turn on the external FET during charge, only during HiZ mode, when the battery is solely supplying the system current. 

    Charge current is the current from the BAT pin to the battery.